Demo Data from SIGIR 2026 / reviewers in the wild / expert
Michael Riegler 0001
dblp:129/8082 · also Michael A. Riegler, Michael Alexander Riegler
· DBLP profile ↗
156ranked-venue papers
11as first author
77since 2021 · last 2026
0000-0002-3153-2064ORCID · conflict
Domains — the database's venue-derived domains; a paper can count in several
Graphics, computer vision, multimedia, augmented reality and games · 100 · 10 first-author · 40 since 2021Artificial intelligence and machine learning · 40 · 23 since 2021Applied, interdisciplinary, general and emerging computing · 28 · 20 since 2021Human-computer interaction and ubiquitous computing · 25 · 16 since 2021Databases, data management, data science and information retrieval · 20 · 1 first-author · 12 since 2021Computer networks · 6 · 2 first-author · 1 since 2021Software engineering, systems software and programming languages · 2 · 2 since 2021
Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.
| Computer graphics and multimedia
10 papers |
Multimedia analysis and retrieval · 45% Multimedia systems and quality of experience · 24% Image and video processing · 21% | |
| Human-computer interaction and pervasive computing
3 papers |
Health and well-being technologies · 78% Games and playful interaction · 12% Immersive interaction · 7% | |
| Interdisciplinary, comprehensive, and emerging computing
6 papers |
Medical and health informatics · 100% | |
| Computer networks
2 papers |
Network measurement and analytics · 58% Content delivery and video streaming · 25% Cellular and mobile networks · 17% | |
| Databases, data mining, and information retrieval
3 papers |
Information retrieval · 74% Machine learning and data management · 17% Web and social media mining · 10% |
Topics — the 20 heaviest of 28, each with the papers that count most for it
| Topic | Weight | Papers | Last | Evidence papers |
|---|---|---|---|---|
Network measurement and analytics
anomaly detection |
0.6 | 1 | 2022 | RCAD: Real-time Collaborative Anomaly Detection System for Mobile Broadband Networks · KDD 2022 |
Information retrieval
multimedia analysis and retrieval |
0.4 | 1 | 2020 | Reproducibility Companion Paper: Instance of Interest Detection · ACM Multimedia 2020 |
Image and video processing › feature representation
deep convolutional features |
0.4 | 1 | 2020 | Reproducibility Companion Paper: Selective Deep Convolutional Features for Image Retrieval · ACM Multimedia 2020 |
Multimedia analysis and retrieval
image retrieval |
0.4 | 1 | 2020 | Reproducibility Companion Paper: Selective Deep Convolutional Features for Image Retrieval · ACM Multimedia 2020 |
Medical and health informatics
gastrointestinal endoscopy |
0.4 | 1 | 2019 | ACM Multimedia BioMedia 2019 Grand Challenge Overview · ACM Multimedia 2019 |
Health and well-being technologies › mental health technology
mixed reality therapy |
0.4 | 1 | 2019 | Using Mr. MAPP for Lower Limb Phantom Pain Management · ACM Multimedia 2019 |
Health and well-being technologies › rehabilitation › neurorehabilitation
phantom limb pain management |
0.4 | 1 | 2019 | Using Mr. MAPP for Lower Limb Phantom Pain Management · ACM Multimedia 2019 |
Visualization and visual analytics
visual analytics |
0.3 | 1 | 2018 | The Importance of Medical Multimedia · ACM Multimedia 2018 |
Medical and health informatics › clinical diagnosis
disease detection |
0.2 | 1 | 2016 | Multimedia and Medicine: Teammates for Better Disease Detection and Survival · ACM Multimedia 2016 |
Multimedia analysis and retrieval › video content analysis
endoscopic video analysis |
0.2 | 1 | 2016 | Multimedia and Medicine: Teammates for Better Disease Detection and Survival · ACM Multimedia 2016 |
Multimedia systems and quality of experience › video quality assessment
full-reference video quality assessment |
0.2 | 1 | 2016 | OpenVQ: A Video Quality Assessment Toolkit · ACM Multimedia 2016 |
Multimedia systems and quality of experience
video quality assessment |
0.2 | 1 | 2016 | OpenVQ: A Video Quality Assessment Toolkit · ACM Multimedia 2016 |
Content delivery and video streaming › 360-degree video streaming
tile-based adaptive streaming |
0.2 | 1 | 2016 | Tiling in Interactive Panoramic Video: Approaches and Evaluation · IEEE Trans. Multim. 2016 |
Image and video processing
image similarity |
0.2 | 1 | 2014 | How 'How' Reflects What's What: Content-based Exploitation of How Users Frame Social Images · ACM Multimedia 2014 |
Games and playful interaction
serious games |
0.2 | 1 | 2014 | Gone: an interactive experience for two people · ACM Multimedia 2014 |
Empirical software engineering
reproducibility |
0.1 | 1 | 2020 | Reproducibility Companion Paper: Selective Deep Convolutional Features for Image Retrieval · ACM Multimedia 2020 |
Immersive interaction › embodiment
virtual embodiment |
0.1 | 1 | 2019 | Using Mr. MAPP for Lower Limb Phantom Pain Management · ACM Multimedia 2019 |
Medical and health informatics › computer-assisted surgery
surgical video analysis |
0.1 | 1 | 2017 | Medical Multimedia Information Systems (MMIS) · ACM Multimedia 2017 |
Image and video processing › real-time image processing
real-time video processing |
0.1 | 1 | 2016 | Multimedia and Medicine: Teammates for Better Disease Detection and Survival · ACM Multimedia 2016 |
Web and social media mining › social media analysis
social image analysis |
0.1 | 1 | 2014 | How 'How' Reflects What's What: Content-based Exploitation of How Users Frame Social Images · ACM Multimedia 2014 |
Methods — techniques the papers use, named apart from their topics
machine learning · 2.1multimodal learning · 0.9deep learning · 0.8unsupervised learning · 0.6hierarchical temporal memory · 0.6distributed learning · 0.6viewport prediction · 0.5video summarization · 0.5sensor fusion · 0.5region-of-interest adaptive quality · 0.5reproducibility · 0.4component analysis · 0.4motion capture · 0.4mixed reality · 0.4perceptual quality modeling · 0.2SSIM · 0.2PSNR · 0.2simsea · 0.2
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | ImageCLEF 2026: Multimodal Challenges in Medicine, Science, Agritech, and Security
Bogdan Ionescu, Henning Müller, Dan-Cristian Stanciu, Ahmedkhan Radzhabov, Alba Garcia Seco de Herrera, Alexandra-Georgiana Andrei, Alexandra Baicoianu, Ana Neacsu, Andrea M. Storås, Asma Ben Abacha, Benjamin Bracke, Lea Reinartz, Benjamin Lecouteux, Christoph M. Friedrich, Cynthia Sabrina Schmidt, Corneliu Florea, Diandra Fabre, Didier Schwab, Dimitar Dimitrov 0003, Emmanuelle Esperança-Rodier, Mihai Gabriel Constantin, Hendrik Damm, Henning Schäfer, Ivan Koychev, Josiane Mothe, Liviu-Daniel Stefan, Maja J. Hjuler, Mehmet Kurt, Meliha Yetisgen, Michael Riegler 0001, Mihai Dogariu, Mihai Ivanovici, Ming Shan Hee, Mohammad El Sakka, Momina Ahsan, Obioma Pelka, Pål Halvorsen, Preslav Nakov, Raphael Brüngel, Steven Alexander Hicks, Sushant Gautam, Tabea Margareta Grace Pakull, Bahadir Eryilmaz, Vajira Thambawita, Vassili Kovalev, Wen-Wai Yim, Yuri Prokopchuk, Zhuohan Xie |
ECIR (4) | 30 |
| 2026 | Low-Dimension Representation Estimation in Principal Component Analysis Under Missing Data
Thanh Tu Do, Van Hua, Uyen Dang, Thu Nguyen 0001, Steven Alexander Hicks, Pål Halvorsen, Michael Riegler 0001, Binh T. Nguyen 0001 |
MMM (2) | 7 |
| 2026 | A Comparative Study of Decoding Strategies in Medical Text Generation
Oriana Presacan, Alireza Nik, Vajira Thambawita, Bogdan Ionescu, Michael Riegler 0001 |
MMM (2) | 5 |
| 2026 | DPERC: Direct Parameter Estimation for Mixed Data with Random Missingness
Tuan L. Vo, Uyen Dang, Thu Nguyen 0001, Pål Halvorsen, Michael Riegler 0001, Binh T. Nguyen 0001 |
MMM (2) | 5 |
| 2026 | Probabilistic Runtime Verification, Evaluation, and Risk Assessment of Visual Deep Learning SystemsabstractDespite achieving excellent performance on benchmarks, deep neural networks often underperform in real-world scenarios due to their sensitivity to minor shifts in input data, referred to as distributional shifts. These shifts are common in practical scenarios but are rarely accounted for during evaluations, leading to inflated performance metrics. To address this gap, we propose a novel methodology for the verification, evaluation, and risk assessment of deep learning systems. Our approach explicitly models the incidence of distributional shifts at run time by estimating their probability from the outputs of out-of-distribution detectors. We combine these estimates with conditional probabilities of network correctness, structuring them in a binary tree. By traversing this tree, we can compute reliable and precise estimates of network accuracy. We assess our approach on five datasets, simulating deployment conditions characterized by different frequencies of distributional shift. Our approach consistently outperforms conventional evaluations, with accuracy estimation errors typically ranging between 0.01 and 0.10. We further showcase the potential of our approach on a medical segmentation benchmark, wherein we apply our methods to risk assessment by associating costs with tree nodes, informing cost–benefit analyses and decision-making. Overall, our approach offers a robust framework for improving the reliability and trustworthiness of deep learning systems, particularly in safety-critical applications, by providing more accurate evaluations and actionable risk assessments. Birk Torpmann-Hagen, Pål Halvorsen, Michael Riegler 0001, Dag Johansen |
ACM Trans. Intell. Syst. Technol. | 3 |
| 2025 | SoccerChat: Integrating Multimodal Data for Enhanced Soccer Game UnderstandingabstractArtificial intelligence (AI) is transforming sports analytics by enabling automated, real-time understanding of soccer matches. Traditional approaches that rely on isolated data streams struggle to capture the full game context. We introduce SoccerChat, a multimodal conversational AI framework that fuses visual and textual information for comprehensive soccer video comprehension. Building on the SoccerNet dataset, we enrich it with jersey color annotations and automatic speech recognition (ASR) transcripts and curate a video-instruction dataset containing 48,677 question-answer (QA) pairs. Fine-tuning Qwen2- VL-7B- Instruct on this resource yields the Soc-cerChat model, which supports accurate event interpretation, classification, and referee assistance. Experiments across action classification and referee QA tasks demonstrate strong general event understanding and competitive officiating analysis. These results highlight the importance of multimodal integration for explainable, interactive, and trustworthy AI-driven sports ana-lytics. Links to the code, dataset, and model weights are available at https://2ithub.com/simula/SoccerChat. Sushant Gautam, Cise Midoglu, Vajira Thambawita, Michael Riegler 0001, Pål Halvorsen, Mubarak Shah |
CBMI | 4 |
| 2025 | Automatic Prompt Generation for Zero-Shot Single Object Frame Segmentation in Videos Using Classification Models: A Polyp Case StudyabstractVideo object segmentation is vital for applications like medical diagnostics, but acquiring dense pixel-level annotations, especially for specialized domains like polyp segmentation, remains a major bottleneck. Foundational models offer zero-shot segmentation but typically require manual prompting, which is impractical for long videos. We propose Map2VidSeg, a novel pipeline that automatically generates prompts from imagelevel classification labels. It leverages localization cues (attention maps/CAMs) from a trained image classifier (ViT/CNN) to create bounding box prompts. These guide an efficient model (YOLOE) with tracking (BOT-SORT) and bidirectional propagation for initial segmentation. Optionally, a high-fidelity model (SAM-2) refines these masks using temporal memory and fusion. Demonstrated on the challenging SUN-SEG benchmark, finetuned DINOv2 (ViT) prompts significantly outperform DenseNet-121 (CNN). Our best configuration (DINOv2+YOLOE+SAM-2 Bidirectional) achieves Dice/mIoU 0.76/0.70 (Easy Unseen) and 0.66/0.60 (Hard Unseen), showcasing the viability of robust video segmentation without segmentation training data. Hanna Borgli, Michael Riegler 0001, Håkon Kvale Stensland, Pål Halvorsen |
CBMS | 2 |
| 2025 | Explanation Supported Learning: Improving Prediction Performance with Explainable Artificial IntelligenceabstractWhen artificial intelligence (AI) and machine learning (ML) models are applied in healthcare, the ability to understand and explain model decisions is an important aspect. Methods in the field of explainable AI (XAI) have been developed to create explanations for such decisions, which provides transparency and trust to the prediction model. However, the use of XAI-based explanations as added data features for the purpose of improving prediction performance remains a little explored topic. Our proposed Explanation Supported Learning (XSL) framework can improve classification performance for ML models used in medical imaging systems, while also providing a new understanding of how medical images are processed by deep learning (DL) models. The XSL framework consists of novel methods to achieve knowledge transfer from one or several teacher models to a student model. The novelty lies in using explanations from the teacher models, obtained from XAI techniques, as added features when training the student model. This approach enables flexible knowledge transfer between models of different architecture types. We further demonstrate how the XSL framework can be used as a new metric for measuring the quality of the explanations provided by XAI methods. The achievement of increased performance in this framework requires that the chosen XAI technique contains useful information based on the learned understanding of the input data by the teacher models. By testing XSL on the HyperKvasir gastrointestinal image dataset, we achieved significant increases in most of the measured classification metrics, and exceeded most benchmark scores of the HyperKvasir paper. Our code is available on GitHub. Adrian Duric, Jim Tørresen, Michael Riegler 0001, Hugo Hammer |
CBMS | 3 |
| 2025 | Point, Detect, Count: Multi-Task Medical Image Understanding with Instruction-Tuned Vision-Language ModelsabstractWe investigate fine-tuning Vision-Language Models (VLMs) for multi-task medical image understanding, focusing on detection, localization, and counting of findings in medical images. Our objective is to evaluate whether instruction-tuned VLMs can simultaneously improve these tasks, with the goal of enhancing diagnostic accuracy and efficiency. Using MedMultiPoints, a multimodal dataset with annotations from endoscopy (polyps and instruments) and microscopy (sperm cells), we reformulate each task into instruction-based prompts suitable for vision-language reasoning. We fine-tune Qwen2.5-VL-7BInstruct using Low-Rank Adaptation (LoRA) across multiple task combinations. Results show that multi-task training improves robustness and accuracy. For example, it reduces the Count Mean Absolute Error (MAE) and increases Matching Accuracy in the Counting + Pointing task. However, trade-offs emerge, such as more zero-case point predictions, indicating reduced reliability in edge cases despite overall performance gains. Our study highlights the potential of adapting general-purpose VLMs to specialized medical tasks via prompt-driven fine-tuning. This approach mirrors clinical workflows, where radiologists simultaneously localize, count, and describe findings - demonstrating how VLMs can learn composite diagnostic reasoning patterns. The model produces interpretable, structured outputs, offering a promising step toward explainable and versatile medical AI. Code, model weights, and scripts will be released for reproducibility at https://github.com/simula/PointDetectCount. Sushant Gautam, Michael Riegler 0001, Pål Halvorsen |
CBMS | 2 |
| 2025 | ImageCLEF 2025: Multimedia Retrieval in Medical, Social Media and Content Recommendation Applications
Bogdan Ionescu, Henning Müller, Dan-Cristian Stanciu, Ahmad Idrissi-Yaghir, Ahmedkhan Radzhabov, Alba Garcia Seco de Herrera, Alexandra-Georgiana Andrei, Andrea M. Storås, Asma Ben Abacha, Benjamin Bracke, Benjamin Lecouteux, Benno Stein 0001, Cécile Macaire, Christoph M. Friedrich, Cynthia Sabrina Schmidt, Diandra Fabre, Didier Schwab, Dimitar Dimitrov 0003, Emmanuelle Esperança-Rodier, Mihai Gabriel Constantin, Helmut Becker, Hendrik Damm, Henning Schäfer, Ivan Rodkin, Ivan Koychev, Johannes Kiesel, Johannes Rückert, Josep Malvehy, Liviu-Daniel Stefan, Louise Bloch, Martin Potthast, Maximilian Heinrich, Michael Riegler 0001, Mihai Dogariu, Noel Codella, Pål Halvorsen, Preslav Nakov, Raphael Brüngel, Roberto A. Novoa, Rocktim Jyoti Das, Steven Alexander Hicks, Sushant Gautam, Tabea Margareta Grace Pakull, Vajira Thambawita, Vassili Kovalev, Wen-Wai Yim, Zhuohan Xie |
ECIR (5) | 33 |
| 2025 | Runtime Verification for Deep Learning Systems
Birk Torpmann-Hagen, Michael Riegler 0001, Pål Halvorsen, Dag Johansen |
ENASE | 2 |
| 2025 | Data Imputation for Noisy Time-Series Data in Healthcare
Lien P. Le, Thi Xuan-Hien Nguyen, Thu Nguyen 0001, Michael Riegler 0001, Pål Halvorsen, Binh T. Nguyen 0001 |
ICCCI (2) | 4 |
| 2025 | ICDAR 25: Intelligent Cross-Data Analysis and RetrievalabstractThe sixth edition of the Intelligent Cross-Data Analysis and Retrieval (ICDAR) workshop continues to serve as a forum for researchers and practitioners addressing the integration, analysis, and retrieval of heterogeneous data sources. While individual modalities such as wearable sensors, lifelogging cameras, and social media have been well studied, analyzing cross-data that incorporates multiple perspectives remains a crucial yet challenging task for advancing human-centered applications. In 2025, the workshop received 19 submissions, of which 7 were accepted following a careful peer-review process, resulting in an acceptance rate of 37%. The accepted papers covered a wide range of topics, including zero-shot composed image retrieval, vision-language scene understanding, adaptive modality fusion, lightweight fine-tuning with truncated SVD, and real-world federated split learning on mobile devices. By fostering interdisciplinary collaboration across domains such as well-being, disaster mitigation, mobility, food computing, and smart cities, the workshop continues to highlight emerging challenges and solutions for building intelligent, sustainable, and human-centric systems driven by cross-modal and multimodal data analytics. Takahiro Komamizu, Marc A. Kastner 0001, Minh-Son Dao, Michael Riegler 0001, Duc-Tien Dang-Nguyen, Son N. Tran |
ICMR | 4 |
| 2025 | Evaluating gradient-based explanation methods for neural network ECG analysis using heatmapsabstractOBJECTIVE: Evaluate popular explanation methods using heatmap visualizations to explain the predictions of deep neural networks for electrocardiogram (ECG) analysis and provide recommendations for selection of explanations methods. MATERIALS AND METHODS: A residual deep neural network was trained on ECGs to predict intervals and amplitudes. Nine commonly used explanation methods (Saliency, Deconvolution, Guided backpropagation, Gradient SHAP, SmoothGrad, Input × gradient, DeepLIFT, Integrated gradients, GradCAM) were qualitatively evaluated by medical experts and objectively evaluated using a perturbation-based method. RESULTS: No single explanation method consistently outperformed the other methods, but some methods were clearly inferior. We found considerable disagreement between the human expert evaluation and the objective evaluation by perturbation. DISCUSSION: The best explanation method depended on the ECG measure. To ensure that future explanations of deep neural networks for medical data analyses are useful to medical experts, data scientists developing new explanation methods should collaborate tightly with domain experts. Because there is no explanation method that performs best in all use cases, several methods should be applied. CONCLUSION: Several explanation methods should be used to determine the most suitable approach. Andrea M. Storås, Steffen Mæland, Jonas Isaksen, Steven Alexander Hicks, Vajira Thambawita, Claus Graff, Hugo Hammer, Pål Halvorsen, Michael Riegler 0001, Jørgen K. Kanters |
J. Am. Medical Informatics Assoc. | 9 |
| 2025 | Validating polyp and instrument segmentation methods in colonoscopy through Medico 2020 and MedAI 2021 ChallengesabstractAutomatic analysis of colonoscopy images has been an active field of research motivated by the importance of early detection of precancerous polyps. However, detecting polyps during the live examination can be challenging due to various factors such as variation of skills and experience among the endoscopists, lack of attentiveness, and fatigue leading to a high polyp miss-rate. Therefore, there is a need for an automated system that can flag missed polyps during the examination and improve patient care. Deep learning has emerged as a promising solution to this challenge as it can assist endoscopists in detecting and classifying overlooked polyps and abnormalities in real time, improving the accuracy of diagnosis and enhancing treatment. In addition to the algorithm’s accuracy, transparency and interpretability are crucial to explaining the whys and hows of the algorithm’s prediction. Further, conclusions based on incorrect decisions may be fatal, especially in medicine. Despite these pitfalls, most algorithms are developed in private data, closed source, or proprietary software, and methods lack reproducibility. Therefore, to promote the development of efficient and transparent methods, we have organized the “Medico automatic polyp segmentation (Medico 2020)” and “MedAI: Transparency in Medical Image Segmentation (MedAI 2021)” competitions. The Medico 2020 challenge received submissions from 17 teams, while the MedAI 2021 challenge also gathered submissions from another 17 distinct teams in the following year. We present a comprehensive summary and analyze each contribution, highlight the strength of the best-performing methods, and discuss the possibility of clinical translations of such methods into the clinic. Our analysis revealed that the participants improved dice coefficient metrics from 0.8607 in 2020 to 0.8993 in 2021 despite adding diverse and challenging frames (containing irregular, smaller, sessile, or flat polyps), which are frequently missed during a routine clinical examination. For the instrument segmentation task, the best team obtained a mean Intersection over union metric of 0.9364. For the transparency task, a multi-disciplinary team, including expert gastroenterologists, accessed each submission and evaluated the team based on open-source practices, failure case analysis, ablation studies, usability and understandability of evaluations to gain a deeper understanding of the models’ credibility for clinical deployment. The best team obtained a final transparency score of 21 out of 25. Through the comprehensive analysis of the challenge, we not only highlight the advancements in polyp and surgical instrument segmentation but also encourage subjective evaluation for building more transparent and understandable AI-based colonoscopy systems. Moreover, we discuss the need for multi-center and out-of-distribution testing to address the current limitations of the methods to reduce the cancer burden and improve patient care. • We present a detailed analysis of the Medico 2020 and MedAI 2021 challenges that are aimed at advancing automated polyp and instrument segmentation in colonoscopy for early colorectal cancer diagnosis by using novel deep learning methods. • To the best of our knowledge, MedAI 2021 is the first challenge to evaluate the transparency in both GI endoscopy and colonoscopy. Through the challenge, we invited the participants to list package dependencies and architecture code (with instructions for building, compiling, and training) and share trained model weights in a standardized format. Additionally, we invited participants to include the code for model evaluation and provide repository licensing information to enable others to use the code and the trained model responsibly. Moreover, we asked the participants to explain model predictions using intermediate heatmaps, perform ablation studies, conduct a thorough failure analysis, and share their code for reproducing the results. Finally, we performed a subjective evaluation by including an expert gastroenterologist in the group and gave the final transparency score based on the usefulness and understandability of the results. Our initiative aims to promote transparency in AI research and foster the development of reliable, interpretable, and trustworthy algorithms for use in medical image segmentation. • We provide a comparative analysis of the 34 proposed methods in both challenges (3 subtasks), covering small details of each team in the form of Tables, qualitative and quantitative results (failure analysis), and an in-depth analysis of the findings. • We explore trust, safety, interpretability, transparency, and generalizability issues and provide future strategies to overcome the current limitations of developed algorithms. Debesh Jha, Vanshali Sharma, Debapriya Banik, Debayan Bhattacharya, Kaushiki Roy, Steven Alexander Hicks, Nikhil Kumar Tomar, Vajira Thambawita, Adrian Krenzer, Ge-Peng Ji, Sahadev Poudel, George Batchkala, Saruar Alam, Awadelrahman M. A. Ahmed, Quoc-Huy Trinh, Zeshan Khan, Tien-Phat Nguyen, Shruti Shrestha, Sabari Nathan, Jeonghwan Gwak, Ritika Kumari Jha, Zheyuan Zhang 0001, Alexander Schlaefer, Debotosh Bhattacharjee, Manas Kamal Bhuyan, Pradip K. Das, Deng-Ping Fan, Sravanthi Parasa, Sharib Ali, Michael Riegler 0001, Pål Halvorsen, Thomas de Lange, Ulas Bagci |
Medical Image Anal. | 30 |
| 2025 | Designing an ethical and explainable automatic coaching (eCoach) system for community based, persuasive recommendationsabstractAbstract This study introduces a community-focused eCoach recommendation system aimed at enhancing physical activity by leveraging demographic data, wearable sensor inputs, and machine learning algorithms to generate both individual and community-based activity recommendations using advice-based collaborative filtering. Existing eCoaching systems largely focus on personalized feedback without incorporating social reinforcement or group-level motivation, creating a gap in leveraging community influence for sustained health behaviors. Our system combines real-time activity tracking through wearable sensors and advice-based collaborative filtering to deliver adaptive recommendations. We collected data from 31 participants (16 using MOX2-5 sensors and 15 from a public Fitbit-based dataset), targeting daily activity levels to generate actionable guidance. Through decision tree classification and SHAP-based interpretability, we achieved a model accuracy of 99.8%, with F1, precision, recall, and MCC metrics confirming robustness across both balanced and imbalanced datasets. Ethical considerations, including privacy, bias mitigation, and informed consent, were integral to our design and implementation. Limitations include potential biases due to sample size and data imbalances, suggesting the need for future validation on independent datasets. This system demonstrates the potential to integrate with real-world healthcare initiatives, offering trust, transparency, and user engagement opportunities to meet public health objectives. Michael Riegler 0001, Pål Halvorsen |
Multim. Tools Appl. | 2 |
| 2024 | Advancing Multimedia Retrieval in Medical, Social Media and Content Recommendation Applications with ImageCLEF 2024
Bogdan Ionescu, Henning Müller, Ana-Maria Claudia Dragulinescu, Ahmad Idrissi-Yaghir, Ahmedkhan Radzhabov, Alba Garcia Seco de Herrera, Alexandra-Georgiana Andrei, Alexandru Stan, Andrea M. Storås, Asma Ben Abacha, Benjamin Lecouteux, Benno Stein 0001, Cécile Macaire, Christoph M. Friedrich, Cynthia Sabrina Schmidt, Didier Schwab, Emmanuelle Esperança-Rodier, George Ioannidis, Griffin Adams, Henning Schäfer, Hugo Manguinhas, Ioan Coman, Johanna Schöler, Johannes Kiesel, Johannes Rückert, Louise Bloch, Martin Potthast, Maximilian Heinrich, Meliha Yetisgen, Michael Riegler 0001, Neal Snider, Pål Halvorsen, Raphael Brüngel, Steven Alexander Hicks, Vajira Thambawita, Vassili Kovalev, Yuri Prokopchuk, Wen-Wai Yim |
ECIR (6) | 30 |
| 2024 | Inducing Inductive Bias in Vision Transformer for EEG ClassificationabstractHuman brain signals are highly complex and dynamic in nature. Electroencephalogram (EEG) devices capture some of this complexity, both in space and in time, with a certain resolution. Recently, transformer-based models have been explored in various applications with different modalities of data. In this work, we introduce a transformer-based model for the classification of EEG signals, inspired by the recent success of the Vision Transformer (ViT) in image classification. Driven by the distinctive characteristics of the EEG data, we design a module that enables us to (1) extract spatio-temporal tokens inherent in the EEG signals and (2) integrate additional non-linearities to capture intricate and non-linear patterns in EEG signals. To that end, we introduce a new lightweight architectural component that combines our proposed attention model with convolution. This convolutional tokenization module forms the basis of our vision backbone referred to as Brain Signal Vision Transformer (BSVT). This architecture takes into account the spatial and temporal features in EEG datasets, leading to token embeddings that effectively capture the fusion of spatial-temporal information. Moreover, while transformer-based models typically perform well when provided with large datasets, here we show that our combination of the inherent inductive bias of Convolutional Neural Networks (CNN) with the transformer enables efficient training from scratch using relatively small datasets, with as few as 0.75M parameters. On the publicly available EEG dataset from Temple University Hospital (TUH Abnormal), our model achieves results comparable or superior to its counterpart ViT model with patchify stem. The implementation is available at https://github.com/IamRabin/BSVT.git Rabindra Khadka, Pedro G. Lind, Gustavo Borges Moreno e Mello, Michael Riegler 0001, Anis Yazidi |
ICASSP | 4 |
| 2024 | Blockwise Principal Component Analysis for monotone missing data imputation and dimensionality reductionabstractMonotone missing data is a common problem in data analysis. However, imputation combined with dimensionality reduction can be computationally expensive, especially with the increasing size of datasets. We propose a Blockwise Principal Component Analysis Imputation (BPI) framework for dimensionality reduction and imputation of monotone missing data to address this issue. The framework conducts Principal Component Analysis on the observed part of each monotone block of the data and then imputes on merging the obtained principal components using a chosen imputation technique. BPI can work with various imputation techniques and can significantly reduce imputation time compared to conducting dimensionality reduction after imputation. This makes it a practical and efficient approach for large datasets with monotone missing data. Our experiments validate the improvement in speed while achieving an accuracy that is comparable to the common strategy of imputation prior to dimensional reduction. Tu T. Do, Anh M. Vu, Tuan L. Vo, Hoang Thien Ly, Thu Nguyen 0001, Steven Alexander Hicks, Pål Halvorsen, Michael Riegler 0001, Binh T. Nguyen 0001 |
IJCNN | 8 |
| 2024 | SoccerNet-Echoes: A Soccer Game Audio Commentary DatasetabstractThe application of Automatic Speech Recognition (ASR) technology in soccer enables sports analytics by extracting audio commentaries to provide insights into game events and facilitate automatic game understanding. This paper presents SoccerNet-Echoes, an extension of the SoccerNet dataset with automatically generated transcriptions of soccer game broadcasts. Generated using the Whisper model and translated with Google Translate into English when needed, these transcriptions enhance video content with textual information derived from game audio. SoccerNet-Echoes serves as a comprehensive resource for developing algorithms in action spotting, caption generation, and game summarization. Through a series of experiments, we demonstrate that combining modalities—audio, video, and text—yields mixed results on classification tasks. The combination of audio and video shows improved performance over individual modalities, while the addition of ASR text does not significantly enhance results. Additionally, our baseline summarization tasks indicate that ASR content enriches summaries, offering insights beyond event information. This multimodal dataset supports diverse applications, broadening the scope of research in sports analytics. The dataset is available at: https://github.com/SoccerNet/sn-echoes. Sushant Gautam, Mehdi Houshmand Sarkhoosh, Jan Held, Cise Midoglu, Anthony Cioppa, Silvio Giancola, Vajira Thambawita, Michael Riegler 0001, Pål Halvorsen, Mubarak Shah |
ISM | 8 |
| 2024 | Overview of the Grand Challenge on Detecting Cheapfakes at ACM ICMR 2024abstractInformation disorder is one of the most typical challenges in the current era of science and technology. The amount of information on the internet is increasing, but its correctness and authenticity are not always guaranteed, leading to false information, fake news, etc. The mentioned problem negatively affects users' reception and use of information. Unlike deepfake, cheapfake is created using simple techniques and does not rely on AI to produce fake multimedia. Cheapfake is becoming increasingly popular due to its ease of creation. Thus, there is a growing need to develop techniques that can detect cheapfake content. Following previous events, the Grand Challenge on Detecting Cheapfakes at ACM ICMR 2024 continues to seek contributions from researchers on cheapfake detection with the goal of improving effectiveness and creativity in approach, and understanding the limitations of the current dataset. This challenge has accepted 6 new proposed methods from participants with the highest private test accuracies achieved at 72.2% for Task 1 and 54.84% for Task 2. The highest public test accuracies for the two tasks are 95.6% and 93% respectively. These new methods focus on incorporating new AI models such as Stable Diffusion, LLM. These new findings represent the latest advancements in cheapfake detection research and introduce new potential approaches for future research. Duc-Tien Dang-Nguyen, Sohail Ahmed Khan, Michael Riegler 0001, Pål Halvorsen, Anh-Duy Tran, Minh-Son Dao, Minh-Triet Tran |
ICMR | 3 |
| 2024 | ICDAR 24: Intelligent Cross-Data Analysis and RetrievalabstractOur workshop aims to provide a platform for both academic and industrial professionals engaged in the analysis and retrieval of cross-data from diverse perspectives, with a particular emphasis on wearable and ambient sensors, lifelog cameras, social networks, and surrounding sensors.Despite numerous studies exploring individual viewpoints, there remains a significant gap in the analysis and retrieval of cross-data to maximize benefits for humanity.Additionally, challenges such as data security and distributed learning for cross-modal model training and inference arise when dealing with large and distributed datasets.We invite researchers to contribute to this initiative, with the overarching goal of fostering the development of a smart and sustainable society through the efficient utilization of intelligent cross-data analysis and retrieval techniques. Minh-Son Dao, Michael Riegler 0001, Duc-Tien Dang-Nguyen, Hanh-Nhi Tran, R. Uday Kiran, Takahiro Komamizu |
ICMR | 2 |
| 2024 | E2Evideo: End to End Video and Image Pre-processing and Analysis Tool
Faiga Alawad, Pål Halvorsen, Michael Riegler 0001 |
MMM (4) | 3 |
| 2024 | Sustainable Commercial Fishery Control Using Multimedia Forensics Data from Non-trusted, Mobile Edge Nodes
Aril B. Ovesen, Tor-Arne S. Nordmo, Michael Riegler 0001, Pål Halvorsen, Dag Johansen |
MMM (3) | 3 |
| 2024 | Correlation Visualization Under Missing Values: A Comparison Between Imputation and Direct Parameter Estimation Methods
Nhat-Hao Pham, Khanh-Linh Vo, Mai Anh Vu, Thu Nguyen 0001, Michael Riegler 0001, Pål Halvorsen, Binh T. Nguyen 0001 |
MMM (4) | 5 |
| 2024 | AI-Based Cropping of Soccer Videos for Different Social Media Representations
Mehdi Houshmand Sarkhoosh, Sayed Mohammad Majidi Dorcheh, Cise Midoglu, Saeed Shafiee Sabet, Tomas Kupka, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
MMM (4) | 7 |
| 2024 | TACDEC: Dataset of Tackle Events in Soccer Game VideosabstractThis paper introduces TACDEC, a dataset of tackle events in soccer game videos. Recognizing the gap in existing open datasets that predominantly focus on official soccer events such as goals and cards, TACDEC targets a comprehensive analysis of tackles --- a critical aspect of soccer that combines technical skills, tactical decision-making, and physical engagement. By leveraging video data from the Norwegian Eliteserien league across multiple seasons, we annotated 425 videos with 4 types of tackle events, categorized into "tackle-live", "tackle-replay", "tackle-live-incomplete", and "tackle-replay-incomplete", yielding a total of 836 event annotations. The dataset offers an unprecedented resource for the development and testing of machine learning models aimed at understanding and analyzing soccer game dynamics. A proof-of-concept classification model demonstrates the dataset's utility, achieving promising results in automatic tackle detection, thereby validating TACDEC's potential to support not only advanced game analytics but also to enhance fan engagement and player development initiatives. Evan Jåsund Kassab, Håkon Maric Solberg, Sushant Gautam, Saeed Shafiee Sabet, Thomas Torjusen, Michael Riegler 0001, Pål Halvorsen, Cise Midoglu |
MMSys | 6 |
| 2024 | An Intent-based Networks Framework based on Large Language ModelsabstractMotivated by the increasing complexity of today’s communication networks, autonomous networks (AN) have recently attracted much attention from industry and academia. Automated network configurations through intent-based networking (IBN) is the first and crucial step towards AN. In this paper, we focus on realizing automated network configurations leveraging the rapid evolution of large language models (LLMs). We proposed a framework based on modular design integrated with LLMs. Our preliminary results confirm that LLMs have great potential in IBN and can serve as an important point on the way to realizing AN while keeping data privacy and integrity of configuration results. However, several challenges and open questions remain to be addressed. Ahlam Fuad, Azza H. Ahmed, Michael Riegler 0001, Tarik Cicic |
NetSoft | 3 |
| 2023 | Predicting Meibomian Gland Dropout and Feature Importance Analysis with Explainable Artificial IntelligenceabstractDry eye disease is a common and potentially debilitating medical condition. Meibum secreted from the meibomian glands is the largest contributor to the outermost, protective lipid layer of the tear film. Dysfunction of the meibomian glands is the most common cause of dry eye disease. As meibomian gland dysfunction progresses, gradual atrophy of the glands is observed. The meibomian glands are commonly visualized through meibography, a technique requiring specialist equipment and knowledge that might not be available to the physician. In the present project we use machine learning on clinical tabular data to predict the degree of meibomian gland dropout. Moreover, we employ explainable artificial intelligence on the best performing algorithms for feature importance evaluation. The best performing algorithms were AdaBoost, multilayer perceptron and LightGBM which outperformed the majority vote baseline classifier in every included evaluation metric for both multioutput and binary classification. Through explainable artificial intelligence known associations are validated and novel connections identified and discussed. Fredrik A. Fineide, Andrea M. Storås, Michael Riegler 0001, Tor Paaske Utheim |
CBMS | 3 |
| 2023 | ML-Peaks: CHIP-Seq Peak Detection Pipeline using Machine Learning TechniquesabstractCHIP-Seq data is critical for identifying the locations where proteins bind to DNA, offering valuable insights into disease molecular mechanisms and potential therapeutic targets. However, identifying regions of protein binding, or peaks, in CHIP-seq data can be challenging due to limitations in peak detection methods. Current computational tools often require manual human inspection using data visualization, making it challenging and resource demanding to detect all peaks, particularly in large datasets. CHIP-seq data poses difficulties in detecting peaks due to its high background noise, low signal-to-noise ratio, and variation in the size and shape of the peaks. To overcome these challenges, we propose a data preprocessing approach using sliding window and feature reduction techniques, and the resulting features can be further used in machine learning methods. Our machine learning methodology can accurately identify peaks using a small training set, which represents a distinct advantage over commonly used statistical approaches, as it has a greater capacity for learning from data. We tested our methodology on the H3K9me3_TDH_BP CHIP-Seq dataset exploring a range of different machine learning methods, sliding window settings, and feature reduction techniques to detect peak values without human intervention. Our pipeline efficiently detected the peaks, and achieved an F1-score of 0.9644 and a false positive rate of 0.1030. Sajad Amouei Sheshkal, Michael Riegler 0001, Hugo Hammer |
CBMS | 2 |
| 2023 | Man vs. AI: An in silico study of polyp detection performanceabstractAI-based colon polyp detection systems have received much attention, and several products and prototypes report good results. In silico verification is a crucial step when developing such systems, but very few compare human versus AI performance. This paper, therefore, describes methods and results for an in silico test of an AI model with two different versions for polyp detection in colonoscopy and compares them to the performance of endoscopist doctors who reviewed the same colonoscopy video clips. The two versions have different thresholds for false positive rate reduction. Our models perform polyp detection within the range of the endoscopists' performance, although faster, showing a potential for use in a clinical setting. For the AI and the endoscopists alike, the results show a trade-off between high sensitivity and high specificity; to achieve perfect detection, one will also get abundance of false positives. This can cause alarm fatigue in a clinical setting. Pia H. Smedsrud, Håvard Espeland, Tor Jan Derek Berstad, Andreas Petlund, Thomas de Lange, Michael Riegler 0001, Pål Halvorsen |
CBMS | 6 |
| 2023 | Identifying Important Proteins in Meibomian Gland Dysfunction with Explainable Artificial IntelligenceabstractMeibomian gland dysfunction is the most common cause of dry eye disease, which is a prevalent condition that can damage the ocular surface and cause reduced vision and substantial pain. Meibum secreted from the meibomian glands makes up the majority of the outer, protective lipid layer of the tear film. Changes in the secreted meibum and markers of glandular damage can be detected through tear sampling. Several studies have investigated the tear film protein expression in meibomian gland dysfunction, but less work apply machine learning to analyze the protein patterns. We use machine learning and methods from explainable artificial intelligence to detect potential clinically relevant proteins in meibomian gland dysfunction. Two different explainable artificial intelligence methods are compared. Several of the proteins found important in the models have been linked to dry eye disease in the past, while some are novel. Consequently, explainable artificial intelligence methods serve as a promising tool for screening for proteins that are relevant for meibomian gland dysfunction. By doing so, one may be able to discover new biomarkers and treatments, and gain a better understanding of how diseases develop. Andrea M. Storås, Morten Magnø, Fredrik A. Fineide, Bernd Thiede, Xiangjun Chen, Inga Strümke, Pål Halvorsen, Tor P. Utheim, Michael Riegler 0001 |
CBMS | 9 |
| 2023 | ImageCLEF 2023 Highlight: Multimedia Retrieval in Medical, Social Media and Content Recommendation Applications
Bogdan Ionescu, Henning Müller, Ana-Maria Claudia Dragulinescu, Adrian Popescu 0001, Ahmad Idrissi-Yaghir, Alba Garcia Seco de Herrera, Alexandra-Georgiana Andrei, Alexandru Stan, Andrea M. Storås, Asma Ben Abacha, Christoph M. Friedrich, George Ioannidis, Griffin Adams, Henning Schäfer, Hugo Manguinhas, Ihar Filipovich, Ioan Coman, Jérôme Deshayes-Chossart, Johanna Schöler, Johannes Rückert, Liviu-Daniel Stefan, Louise Bloch, Meliha Yetisgen, Michael Riegler 0001, Mihai Dogariu, Mihai Gabriel Constantin, Neal Snider, Nikolaos Papachrysos, Pål Halvorsen, Raphael Brüngel, Serge Kozlovski, Steven Alexander Hicks, Thomas de Lange, Vajira Thambawita, Vassili Kovalev, Wen-Wai Yim |
ECIR (3) | 24 |
| 2023 | Combining datasets to improve model fittingabstractFor many use cases, combining information from different datasets can be of interest to improve a machine learning model's performance, especially when the number of samples from at least one of the datasets is small. An additional challenge in such cases is that the features from these datasets are not identical, even though there are some commonly shared features among the datasets. To tackle this, we propose a novel framework called Combine datasets based on Imputation (ComImp). In addition, we propose PCA-ComImp, a variant of ComImp that utilizes Principle Component Analysis (PCA), where dimension reduction is conducted before combining datasets. This is useful when the datasets have a large number of features that are not shared across them. Furthermore, our framework can also be utilized for data preprocessing by imputing missing data, i.e., filling in the missing entries while combining different datasets. To illustrate the performance and practicability of the proposed methods and their potential usages, we conduct experiments for various tasks (regression, classification) and for different data types (tabular data, time series data) when the datasets to be combined have missing data. We also investigate how the devised methods can be used with transfer learning to provide even further model training improvement. Our results indicate that can provide extra improvement when being used in combination with transfer learning. Thu Nguyen 0001, Rabindra Khadka, Nhan Phan, Anis Yazidi, Pål Halvorsen, Michael Riegler 0001 |
IJCNN | 6 |
| 2023 | SmartCrop: AI-Based Cropping of Soccer VideosabstractIn the rapidly evolving landscape of digital platforms, the need for optimizing media representations to cater to various aspect ratios is palpable. In this paper, we pioneer an approach that utilizes object detection, scene detection, outlier detection, and interpolation for smart cropping. Using soccer as a case study, our primary goal is to capture the frame salience using object (player and ball) detection and tracking using AI models. To improve the object detection and tracking, we rely on scene understanding and explore various outlier detection and interpolation techniques. Our pipeline, called SmartCrop, is efficient, and supports various configurations for object tracking, interpolation, and outlier detection to find the best point-of-interest to be used as the cropping center of the video frame. An objective evaluation of the performance of individual pipeline components has validated our proposed architecture and the need for object, scene, outlier detection, and interpolation. Moreover, a crowdsourced subjective user study, assessing the alternative approaches for cropping from 16:9 to 1:1 and 9:16 aspect ratios, confirms that our proposed approach increases the end-user Quality of Experience (QoE). Sayed Mohammad Majidi Dorcheh, Mehdi Houshmand Sarkhoosh, Cise Midoglu, Saeed Shafiee Sabet, Tomas Kupka, Michael Riegler 0001, Dag Johansen, Pål Halvorsen |
ISM | 6 |
| 2023 | ICDAR'23: Intelligent Cross-Data Analysis and RetrievalabstractRecently, there has been an increased interest in cross-data research problems, such as predicting air quality using life logging images, predicting congestion using weather and tweets data, and predicting sleep quality using daily exercises and meals. Although several research focusing on multimodal data analytics have been performed, few studies have been conducted on cross-data research (e.g., cross-modal data, cross-domain, cross-platform). The article collection “Intelligent Cross-Data Analysis and Retrieval” aims to encourage research in intelligent cross-data analytics and retrieval and contribute to the creation of a sustainable society. Researchers from diverse domains such as well-being, disaster prevention and mitigation, mobility, climate, tourism and healthcare are welcome to contribute to this Research Topic. Guillaume Habault, Minh-Son Dao, Michael Riegler 0001, Duc-Tien Dang-Nguyen, Yuta Nakashima, Cathal Gurrin |
ICMR | 3 |
| 2023 | Multimedia Datasets: Challenges and Future Possibilities
Thu Nguyen 0001, Andrea M. Storås, Vajira Thambawita, Steven Alexander Hicks, Pål Halvorsen, Michael Riegler 0001 |
MMM (2) | 6 |
| 2023 | Generation of Synthetic Tabular Healthcare Data Using Generative Adversarial Networks
Alireza Hossein Zadeh Nik, Michael Riegler 0001, Pål Halvorsen, Andrea M. Storås |
MMM (1) | 2 |
| 2023 | Arctic HARE: A Machine Learning-Based System for Performance Analysis of Cross-Country Skiers
Tor-Arne S. Nordmo, Michael Riegler 0001, Håvard D. Johansen, Dag Johansen |
MMM (1) | 2 |
| 2023 | ScopeSense: An 8.5-Month Sport, Nutrition, and Lifestyle Lifelogging DatasetabstractNowadays, most people have a smartphone that can track their everyday activities. Furthermore, a significant number of people wear advanced smartwatches to track several vital biomarkers in addition to activity data. However, it is still unclear how these data can actually be used to improve certain aspects of people’s lives. One of the key challenges is that the collected data is often massive and unstructured. Therefore, a link to other important information (e.g., when, what, and how much food was consumed) is required. It is widely believed that such detailed and structured longitudinal data about a person is essential to model and provide personalized and precise guidance. Despite the strong belief of researchers about the power of such a data-driven approach, respective datasets have been difficult to collect. In this study, we present a unique dataset from two individuals performing a structured data collection over eight and a half months. In addition to the sensor data, we collected their nutrition, training, and well-being data. The availability of nutrition data with many other important objectives and subjective longitudinal data streams may facilitate research related to food for a healthy lifestyle. Thus, we present a sport, nutrition, and lifestyle logging dataset called ScopeSense from two individuals and discuss its potential use. The dataset is fully open for researchers, and we consider this study as a potential starting point for developing methods to collect and create knowledge for a larger cohort of people. Michael Riegler 0001, Vajira Thambawita, Binh T. Nguyen 0001, Steven Alexander Hicks, Vibeke Telle-Hansen, Svein Arne Pettersen, Dag Johansen, Ramesh Jain 0001, Pål Halvorsen |
MMM (1) | 1 |
| 2023 | Efficient quantile tracking using an oracleabstractAbstract Concept drift is a well-known issue that arises when working with data streams. In this paper, we present a procedure that allows a quantile tracking procedure to cope with concept drift. We suggest using expected quantile loss, a popular loss function in quantile regression, to monitor the quantile tracking error, which, in turn, is used to efficiently adapt to concept drift. The suggested procedures adapt efficiently to concept drift, and the tracking performance is close to theoretically optimal. The procedures were further applied to three real-life streaming data sets related to Twitter event detection, activity recognition, and stock trading. The results show that the procedures are efficient at adapting to concept drift, thereby documenting the real-world applicability of the procedures. We further used asymptotic theory from statistics to show the appealing theoretical property that, if the data stream distribution is stationary over time, the procedures converge to the true quantile. Hugo Hammer, Anis Yazidi, Michael Riegler 0001, Håvard Rue |
Appl. Intell. | 3 |
| 2023 | Prediction of schizophrenia from activity data using hidden Markov model parameters
Matthias Boeker, Hugo Hammer, Michael Riegler 0001, Pål Halvorsen, Petter Jakobsen |
Neural Comput. Appl. | 3 |
| 2023 | FANet: A Feedback Attention Network for Improved Biomedical Image SegmentationabstractThe increase of available large clinical and experimental datasets has contributed to a substantial amount of important contributions in the area of biomedical image analysis. Image segmentation, which is crucial for any quantitative analysis, has especially attracted attention. Recent hardware advancement has led to the success of deep learning approaches. However, although deep learning models are being trained on large datasets, existing methods do not use the information from different learning epochs effectively. In this work, we leverage the information of each training epoch to prune the prediction maps of the subsequent epochs. We propose a novel architecture called feedback attention network (FANet) that unifies the previous epoch mask with the feature map of the current training epoch. The previous epoch mask is then used to provide hard attention to the learned feature maps at different convolutional layers. The network also allows rectifying the predictions in an iterative fashion during the test time. We show that our proposed feedback attention model provides a substantial improvement on most segmentation metrics tested on seven publicly available biomedical imaging datasets demonstrating the effectiveness of FANet. The source code is available at https://github.com/nikhilroxtomar/FANet. Nikhil Kumar Tomar, Debesh Jha, Michael Riegler 0001, Håvard D. Johansen, Dag Johansen, Jens Rittscher, Pål Halvorsen, Sharib Ali |
IEEE Trans. Neural Networks Learn. Syst. | 3 |
| 2022 | A Virtual Reality Talking Avatar for Investigative Interviews of Maltreat ChildrenabstractInterviews conducted with the maltreated children are often the primary source of evidence in prosecution. Many alleged incidents of abuse are not prosecuted because the children’s testimony is collected in an unreliable way. Research shows the consistent poor quality of these interviews and highlights the need for better training of Child Protection Services (CPS) and police personnel who interview abused child witnesses. The currently available systems for training of CPS and police personnel are developed in a rigid way that lag behind in generating dynamic responses. Moreover, these systems require human input such as employing an actor mimicking a child or an operator controlling prerecorded child responses during the interactions. This paper demonstrates the prototype of an interview training program with an artificial intelligent Child Avatar in Virtual Reality (VR), enabling CPS and police personnel to practice interviewing with abused children. The program is developed using Unity game engine and artificial intelligence-based technologies such as dialogue models, talking visual avatars, text-to-speech, and speech-to-text components. Syed Zohaib Hassan, Pegah Salehi, Michael Riegler 0001, Miriam S. Johnson, Gunn Astrid Baugerud, Pål Halvorsen, Saeed Shafiee Sabet |
CBMI | 3 |
| 2022 | PolypConnect: Image inpainting for generating realistic gastrointestinal tract images with polypsabstractEarly identification of a polyp in the lower gas-trointestinal (GI) tract can lead to prevention of life-threatening colorectal cancer. Developing computer-aided diagnosis (CAD) systems to detect polyps can improve detection accuracy and efficiency and save the time of the domain experts called endoscopists. Lack of annotated data is a common challenge when building CAD systems. Generating synthetic medical data is an active research area to overcome the problem of having relatively few true positive cases in the medical domain. To be able to efficiently train machine learning (ML) models, which are the core of CAD systems, a considerable amount of data should be used. In this respect, we propose the PolypConnect pipeline, which can convert non-polyp images into polyp images to increase the size of training datasets for training. We present the whole pipeline with quantitative and qualitative evaluations involving endoscopists. The polyp segmentation model trained using synthetic data, and real data shows a 5.1% improvement of mean intersection over union (mIOU), compared to the model trained only using real data. The codes of all the experiments are available on GitHub to reproduce the results. Jan Andre Fagereng, Vajira Thambawita, Andrea M. Storås, Sravanthi Parasa, Thomas de Lange, Pål Halvorsen, Michael Riegler 0001 |
CBMS | 7 |
| 2022 | Estimating Predictive Uncertainty in Gastrointestinal Polyp SegmentationabstractDeep neural networks have achieved state-of-the-art performance on numerous applications in the medical field, with use-cases ranging from automation of mundane tasks to diagnosis of life-threatening diseases. Despite these achievements, deep neural networks are considered “black boxes” due to their complex structure and general lack of transparency in their decision-making process. These attributes make it challenging to incorporate deep learning into existing clinical workflows as decisions often need more support than blind faith in a statistical model. This paper presents an investigation of uncertainty estimation for the detection of colon polyps using deep convolutional neural networks (CNNs). We experiment with two different approaches to measure uncertainty, Monte Carlo (MC) dropout and deep ensembles, and discuss the advantages and disadvantages of both methods in terms of computational efficiency and performance gain. Furthermore, we apply the two uncertainty methods to two different state-of-the-art CNN-based polyp segmentation architectures. The uncertainty is visualized as heatmaps on the input images and can be used to make more informed decisions on whether or not to trust a model's predictions. The results show that the predictive uncertainties provide a comparison between different models' predictions which can be interpreted as contrastive explanations where the values are largely influenced by the degree of independence between the models in the ensemble. We also reveal that MC dropout is shown to lack at providing contrastive uncertainty values due to the high correlation between the models' in the ensemble. Felicia Ly Jacobsen, Steven Alexander Hicks, Pål Halvorsen, Michael Riegler 0001 |
CBMS | 4 |
| 2022 | Predicting Tacrolimus Exposure in Kidney Transplanted Patients Using Machine LearningabstractTacrolimus is one of the cornerstone immunosup-pressive drugs in most transplantation centers worldwide following solid organ transplantation. Therapeutic drug monitoring of tacrolimus is necessary in order to avoid rejection of the transplanted organ or severe side effects. However, finding the right dose for a given patient is challenging, even for experienced clinicians. Consequently, a tool that can accurately estimate the drug exposure for individual dose adaptions would be of high clinical value. In this work, we propose a new technique using machine learning to estimate the tacrolimus exposure in kidney transplant recipients. Our models achieve predictive errors that are at the same level as an established population pharmacokinetic model, but are faster to develop and require less knowledge about the pharmacokinetic properties of the drug. Andrea M. Storås, Anders Åsberg, Pål Halvorsen, Michael Riegler 0001, Inga Strümke |
CBMS | 4 |
| 2022 | Parallel feature selection based on the trace ratio criterionabstractThe growth of data today poses a challenge in management and inference. While feature extraction methods are capable of reducing the size of the data for inference, they do not help in minimizing the cost of data storage. On the other hand, feature selection helps to remove the redundant features and therefore is helpful not only in inference but also in reducing management costs. This work presents a novel parallel feature selection approach for classification, namely Parallel Feature Selection using Trace criterion (PFST), which scales up to very large datasets. Our method uses trace criterion, a measure of class separability used in Fisher's Discriminant Analysis, to evaluate feature usefulness. We analyzed the criterion's desirable properties theoretically. Based on the criterion, PFST rapidly finds important features out of a set of features for big datasets by first making a forward selection with early removal of seemingly redundant features parallelly. After the most important features are included in the model, we check back their contribution for possible interaction that may improve the fit. Lastly, we make a backward selection to check back possible redundant added by the forward steps. We evaluate our methods via various experiments using Linear Discriminant Analysis as the classifier on selected features. The experiments show that our method can produce a small set of features in a fraction of the amount of time by the other methods under comparison. In addition, the classifier trained on the features selected by PFST not only achieves better accuracy than the ones chosen by other approaches, but can also achieve better accuracy than the classification on all available features. Thu Nguyen 0001, Thanh Nhan Phan, Van Nhuong Nguyen, Binh T. Nguyen 0001, Pål Halvorsen, Michael Riegler 0001 |
IJCNN | 6 |
| 2022 | A Comparative Study of Interactive Environments for Investigative Interview of A Virtual Child AvatarabstractIn cases of suspected child abuse, police and child protection services (CPS) personnel often conduct investigative interviews. These interviews are intended to obtain a reliable account from the child about the alleged crime so that proper legal and clinical interventions can be implemented, with the prosecution presenting the case in court. Studies show that the quality of these interviews is often poor, and interviewers’ current training programs are not that efficient. Training must be spaced and repeated over time. In this paper, we present a system that simulates the scenario of interviewing a victim of child sexual abuse in four different interactive environments. We conducted a user study in which participating experts interviewed a simulated child to determine which interactive environment would provide the highest quality of experience (QoE) and motivates experts for higher practice time with the system. The experts include CPS workers and child welfare students. This study measures each user interaction’s overall QoE, realism, responsiveness, presence, and flow as well as the learning effects, engagement in learning, and self-efficacy. The study shows that 66% of the participants would prefer to use virtual reality (VR) for interactive training over other environments. VR had the highest rate in most of the assessment metrics. Syed Zohaib Hassan, Saeed Shafiee Sabet, Pegah Salehi, Hayley Ko, Ingvild Riiser, Miriam S. Johnson, Gunn Astrid Baugerud, Michael Riegler 0001, Pål Halvorsen |
ISM | 8 |
| 2022 | Experiences and Lessons Learned from a Crowdsourced-Remote Hybrid User Survey FrameworkabstractSubjective user studies are important to ensure the fidelity and usability of systems that generate multimedia content. Testing how end-users and domain experts perceive multimedia assets might provide crucial information. In this paper, we present our experiences with the open source hybrid crowdsourced-remote user survey framework called Huldra, which is intended for conducting web-based subjective user studies and aims to integrate the individual benefits associated with traditional, crowdsourced, and remote methods. We disseminate our experiences and insights from two actively deployed use cases and discuss challenges and opportunities associated with using Huldra as a framework for conducting user studies. Cise Midoglu, Andrea M. Storås, Saeed Shafiee Sabet, Malek Hammou, Steven Alexander Hicks, Inga Strümke, Michael Riegler 0001, Carsten Griwodz, Pål Halvorsen |
ISM | 7 |
| 2022 | Detection of Commercial Fishing-related Slipping Events using Multimodal DataabstractSlipping, or deliberate release, of dead or dying fish is a potentially illegal act, depending on the fish species and jurisdiction where the fish was caught. These events are extremely difficult to regulate, due to fishing vessels being far out to sea and spread out across a large area. Therefore, detecting such events manually using inspection boats is infeasible. However, slipping events can lead to release of fish oil, if the fish dies as part of the release process, which can be detected in satellite imagery given good detection capabilities. We propose an approach to detect fishing vessels that might have deliberately released fish they have caught. The method we propose is to analyze multiple sources of data simultaneously and combine it, using positional data, sales notes, oil slick detection and satellite-based vessel detection. Our experimental results show that we are able to provide a ranking of suspicious vessels that can be used for further investigations. Tor-Arne S. Nordmo, Martine Mostervik Espeseth, Bjørn Aslak Juliussen, Michael Riegler 0001, Dag Johansen |
ISM | 4 |
| 2022 | Segmentation Consistency Training: Out-of-Distribution Generalization for Medical Image SegmentationabstractGeneralizability is seen as one of the major challenges in deep learning, in particular in the domain of medical imaging, where a change of hospital or in imaging routines can lead to a complete failure of a model. To tackle this, we introduce Consistency Training, a training procedure and alternative to data augmentation based on maximizing models’ prediction consistency across augmented and unaugmented data in order to facilitate better out-of-distribution generalization. To this end, we develop a novel auxiliary region-based segmentation loss function called Segmentation Inconsistency Loss (SIL), which considers the differences between pairs of augmented and unaugmented predictions and labels. We demonstrate that Consistency Training outperforms conventional data augmentation on several out-of-distribution datasets on polyp segmentation, a popular medical task. Birk Torpmann-Hagen, Vajira Thambawita, Michael Riegler 0001, Pål Halvorsen, Kyrre Glette |
ISM | 3 |
| 2022 | RCAD: Real-time Collaborative Anomaly Detection System for Mobile Broadband NetworksabstractThe rapid increase in mobile data traffic and the number of connected devices and applications in networks is putting a significant pressure on the current network management approaches that heavily rely on human operators. Consequently, an automated network management system that can efficiently predict and detect anomalies is needed. In this paper, we propose, RCAD, a novel distributed architecture for detecting anomalies in network data forwarding latency in an unsupervised fashion. RCAD employs the hierarchical temporal memory (HTM) algorithm for the online detection of anomalies. It also involves a collaborative distributed learning module that facilitates knowledge sharing across the system. We implement and evaluate RCAD on real world measurements from a commercial mobile network. RCAD achieves over 0.7 F-1 score significantly outperforming current state-of-the-art methods. Azza H. Ahmed, Michael Riegler 0001, Steven Alexander Hicks, Ahmed Elmokashfi |
KDD | 2 |
| 2022 | ICDAR'22: Intelligent Cross-Data Analysis and RetrievalabstractWe have witnessed the rise of cross-data against multimodal data problems recently. The cross-modal retrieval system uses a textual query to look for images; the air quality index can be predicted using lifelogging images; the congestion can be predicted using weather and tweets data; daily exercises and meals can help to predict the sleeping quality are some examples of this research direction. Although vast investigations focusing on multimodal data analytics have been developed, few cross-data (e.g., cross-modal data, cross-domain, cross-platform) research has been carried on. In order to promote intelligent cross-data analytics and retrieval research and to bring a smart, sustainable society to human beings, the specific article collection on "Intelligent Cross-Data Analysis and Retrieval" is introduced. This Research Topic welcomes those who come from diverse research domains and disciplines such as well-being, disaster prevention and mitigation, mobility, climate change, tourism, healthcare, and food computing Minh-Son Dao, Michael Riegler 0001, Duc-Tien Dang-Nguyen, Cathal Gurrin, Yuta Nakashima, Mianxiong Dong |
ICMR | 2 |
| 2022 | Huldra: a framework for collecting crowdsourced feedback on multimedia assetsabstractCollecting crowdsourced feedback to evaluate, rank, or score multimedia content can be cumbersome and time-consuming. Most of the existing survey tools are complicated, hard to customize, or tailored for a specific asset type. In this paper, we present an open source framework called Huldra, designed explicitly to address the challenges associated with user studies involving crowdsourced feedback collection. The web-based framework is built in a modular and configurable fashion to allow for the easy adjustment of the user interface (UI) and the multimedia content, while providing integrations with reliable and stable backend solutions to facilitate the collection and analysis of responses. Our proposed framework can be used as an online survey tool by researchers working on different topics such as Machine Learning (ML), audio, image, and video quality assessment, Quality of Experience (QoE), and require user studies for the benchmarking of various types of multimedia content. Malek Hammou, Cise Midoglu, Steven Alexander Hicks, Andrea M. Storås, Saeed Shafiee Sabet, Inga Strümke, Michael Riegler 0001, Pål Halvorsen |
MMSys | 7 |
| 2022 | Automatic thumbnail selection for soccer videos using machine learningabstractThumbnail selection is a very important aspect of online sport video presentation, as thumbnails capture the essence of important events, engage viewers, and make video clips attractive to watch. Traditional solutions in the soccer domain for presenting highlight clips of important events such as goals, substitutions, and cards rely on the manual or static selection of thumbnails. However, such approaches can result in the selection of sub-optimal video frames as snapshots, which degrades the overall quality of the video clip as perceived by viewers, and consequently decreases viewership, not to mention that manual processes are expensive and time consuming. In this paper, we present an automatic thumbnail selection system for soccer videos which uses machine learning to deliver representative thumbnails with high relevance to video content and high visual quality in near real-time. Our proposed system combines a software framework which integrates logo detection, close-up shot detection, face detection, and image quality analysis into a modular and customizable pipeline, and a subjective evaluation framework for the evaluation of results. We evaluate our proposed pipeline quantitatively using various soccer datasets, in terms of complexity, runtime, and adherence to a pre-defined rule-set, as well as qualitatively through a user study, in terms of the perception of output thumbnails by end-users. Our results show that an automatic end-to-end system for the selection of thumbnails based on contextual relevance and visual quality can yield attractive highlight clips, and can be used in conjunction with existing soccer broadcast pipelines which require real-time operation. Andreas Husa, Cise Midoglu, Malek Hammou, Steven Alexander Hicks, Dag Johansen, Tomas Kupka, Michael Riegler 0001, Pål Halvorsen |
MMSys | 7 |
| 2022 | HOST-ATS: automatic thumbnail selection with dashboard-controlled ML pipeline and dynamic user surveyabstractWe present HOST-ATS, a holistic system for the automatic selection and evaluation of soccer video thumbnails, which is composed of a dashboard-controlled machine learning (ML) pipeline, and a dynamic user survey. The ML pipeline uses logo detection, close-up shot detection, face detection, image quality prediction, and blur detection to automatically select thumbnails from soccer videos in near real-time, and can be configured via a graphical user interface. The web-based dynamic user survey can be employed to qualitatively evaluate the thumbnails selected by the pipeline. The survey is fully configurable and easy to update via continuous integration, allowing for the dynamic aggregation of participant responses to different sets of multimedia assets. We demonstrate the configuration and execution of the ML pipeline via the custom dashboard, and the agile (re-)deployment of the user survey via Firebase and Heroku cloud service integrations, where the audience can interact with configuration parameter updates in real-time. Our experience with HOST-ATS shows that an automatic thumbnail selection system can yield highly attractive highlight clips, and can be used in conjunction with existing soccer broadcast practices in real-time. Andreas Husa, Cise Midoglu, Malek Hammou, Pål Halvorsen, Michael Riegler 0001 |
MMSys | 5 |
| 2022 | Njord: a fishing trawler datasetabstractFish is one of the main sources of food worldwide. The commercial fishing industry has a lot of different aspects to consider, ranging from sustainability to reporting. The complexity of the domain also attracts a lot of research from different fields like marine biology, fishery sciences, cybernetics, and computer science. In computer science, detection of fishing vessels via for example remote sensing and classification of fish from images or videos using machine learning or other analysis methods attracts growing attention. Surprisingly, little work has been done that considers what is happening on board the fishing vessels. On the deck of the boats, a lot of data and important information are generated with potential applications, such as automatic detection of accidents or automatic reporting of fish caught. This paper presents Njord, a fishing trawler dataset consisting of surveillance videos from a modern off-shore fishing trawler at sea. The main goal of this dataset is to show the potential and possibilities that analysis of such data can provide. In addition to the data, we provide a baseline analysis and discuss several possible research questions this dataset could help answer. Tor-Arne S. Nordmo, Aril B. Ovesen, Bjørn Aslak Juliussen, Steven Alexander Hicks, Vajira Thambawita, Håvard D. Johansen, Pål Halvorsen, Michael Riegler 0001, Dag Johansen |
MMSys | 8 |
| 2022 | Explainability methods for machine learning systems for multimodal medical datasets: research proposalabstractThis paper contains the research proposal of Andrea M. Storås that was presented at the MMSys 2022 doctoral symposium. Machine learning models have the ability to solve medical tasks with a high level of performance, e.g., classifying medical videos and detecting anomalies using different sources of data. However, many of these models are highly complex and difficult to understand. Lack of interpretability can limit the use of machine learning systems in the medical domain. Explainable artificial intelligence provides explanations regarding the models and their predictions. In this PhD project, we develop machine learning models for automatic analysis of medical data and explain the results using established techniques from the field of explainable artificial intelligence. Current research indicate that there are still open issues to be solved in order for end users to understand multimedia systems powered by machine learning. Consequently, new explanation techniques will also be developed. Different types of medical data are applied in order to investigate the generalizability of the methods. Andrea M. Storås, Inga Strümke, Michael Riegler 0001, Pål Halvorsen |
MMSys | 3 |
| 2022 | Human vs. GPT-3: The challenges of extracting emotions from child responsesabstractConducting interviews with abused children requires a specific skill set that is obtained by undergoing special training. In addition to acquiring the interview training skills, these also have to be constantly refreshed to keep a high level of quality. Technology, such as synthetic video generation and natural language processing, is in a stage that could allow the construction of a system that can make this task easier. Thus, we aim to design a training system aided by machine learning that can support the interview training with an interactive child avatar capable of meaningful interactions with the trainees. In these interviews, emotions play an important role, so we conduct three different user studies in a remote study setting with the aim of analyzing child emotions in these interviews. In these user studies, the participants had to classify different transcripts excerpts as one of the possible predefined emotions. These human annotations are used to measure the performance of sentiment analysis using GPT-3. We investigate different approaches to obtain the correct classifications by changing the amount of context the participants and the model get to see. Our experiments show that humans have a hard time agreeing when choosing between seven different emotions. This improves when we reduce the set of emotions to four. In addition, we found that context is needed to make a motivated choice, but too much context can make it vague, reducing the judgment's quality. Myrthe Lammerse, Syed Zohaib Hassan, Saeed Shafiee Sabet, Michael Riegler 0001, Pål Halvorsen |
QoMEX | 4 |
| 2022 | When Every Millisecond Counts: The Impact of Delay in VR GamingabstractThis paper presents the finding of a subjective study investigating the impact of delay on a VR gaming experience, applying an experimental design to a virtual game of squash. 32 participants were asked to rate the stability of the VR experience while playing the game, with results showing an impact of delay even at the lowest level of 20 ms added delay. With 120 ms added delay, most participants judged the experience to be fully unstable. Exploring individual differences, we also found that males and experienced gamers were more critical, or more sensitive, to higher levels of delay, compared to females and less experienced gamers. Saeed Shafiee Sabet, Ragnhild Eg, Kjetil Raaen, Muhammad Oasim, Michael Riegler 0001, Pål Halvorsen |
QoMEX | 5 |
| 2022 | Comparison of Crowdsourced and Remote Subjective User Studies: A Case Study of Investigative Child InterviewsabstractCrowdsourced and remote user studies have recently gained popularity as alternatives to traditional laboratory studies. However, they are subject to unreliability, and it is challenging to ensure that valid results are collected, especially when conducting user studies with experts. Experts are a sparse resource, usually having busy schedules and heavy workloads, and are not necessarily geographically close. They are therefore often unwilling to participate in studies which require physical attendance. In this paper, we compare three alternative methods: crowd sourced user study with non-experts, remote user study with non-experts, and remote user study with domain experts, for a use case involving investigative child interview training. We present the results from three subjective studies about the perception of AI-generated child avatars, which is developed using various technologies such as dialogue models, game engine, text-to-speech and speech-to-text components. The study was conducted with three different user groups, and our results indicate the importance of using best practice measures for ensuring the collection of reliable results in crowdsourced settings as compared to remote studies, and highlight the difference between the perspectives of domain experts and non-experts. Saeed Shafiee Sabet, Cise Midoglu, Syed Zohaib Hassan, Pegah Salehi, Gunn Astrid Baugerud, Carsten Griwodz, Miriam S. Johnson, Michael Riegler 0001, Pål Halvorsen |
QoMEX | 8 |
| 2022 | LSTM Step Prediction and Ontology-Based Recommendation Generation in Activity eCoachingabstractAn eCoach system may allow people to manage a healthy lifestyle with health state monitoring (e.g., physical activity) and personalized recommendation generation. Daily step count is an important feature to provide a direct and indirect reflection on individual activity levels. Therefore, a personalized, predictive model may be beneficial to forecast future “steps” to motivate participants based on the temporal “step” pattern. Here, we have conceptualized the idea with a Bidirectional Long-ShortTerm-Memory (LSTM) model for weekly activity forecasting and a rule-base for personalized recommendation generation with Ontology reasoning and querying in activity eCoaching. First, we have used the publicly available “PMData” dataset of 16 adults (M: 13; F: 3) to train and test the models and explore the possibility of accurate univariate time-series forecasting of “step counts”. Second, we have created an Ontology and a rule-base to generate personalized activity recommendations to motivate participants to accomplish their activity goals (e.g., complete “X” steps daily and stay active for the entire week). Nibedita Pahari, Michael Riegler 0001, Andreas Prinz 0001 |
WiMob | 3 |
| 2022 | MSRF-Net: A Multi-Scale Residual Fusion Network for Biomedical Image SegmentationabstractMethods based on convolutional neural networks have improved the performance of biomedical image segmentation. However, most of these methods cannot efficiently segment objects of variable sizes and train on small and biased datasets, which are common for biomedical use cases. While methods exist that incorporate multi-scale fusion approaches to address the challenges arising with variable sizes, they usually use complex models that are more suitable for general semantic segmentation problems. In this paper, we propose a novel architecture called Multi-Scale Residual Fusion Network (MSRF-Net), which is specially designed for medical image segmentation. The proposed MSRF-Net is able to exchange multi-scale features of varying receptive fields using a Dual-Scale Dense Fusion (DSDF) block. Our DSDF block can exchange information rigorously across two different resolution scales, and our MSRF sub-network uses multiple DSDF blocks in sequence to perform multi-scale fusion. This allows the preservation of resolution, improved information flow and propagation of both high- and low-level features to obtain accurate segmentation maps. The proposed MSRF-Net allows to capture object variabilities and provides improved results on different biomedical datasets. Extensive experiments on MSRF-Net demonstrate that the proposed method outperforms the cutting-edge medical image segmentation methods on four publicly available datasets. We achieve the Dice Coefficient (DSC) of 0.9217, 0.9420, and 0.9224, 0.8824 on Kvasir-SEG, CVC-ClinicDB, 2018 Data Science Bowl dataset, and ISIC-2018 skin lesion segmentation challenge dataset respectively. We further conducted generalizability tests and achieved DSC of 0.7921 and 0.7575 on CVC-ClinicDB and Kvasir-SEG, respectively. Debesh Jha, Sukalpa Chanda, Umapada Pal 0001, Håvard D. Johansen, Dag Johansen, Michael Riegler 0001, Sharib Ali, Pål Halvorsen |
IEEE J. Biomed. Health Informatics | 7 |
| 2022 | Artificial Intelligence for Colonoscopy: Past, Present, and FutureabstractDuring the past decades, many automated image analysis methods have been developed for colonoscopy. Real-time implementation of the most promising methods during colonoscopy has been tested in clinical trials, including several recent multi-center studies. All trials have shown results that may contribute to prevention of colorectal cancer. We summarize the past and present development of colonoscopy video analysis methods, focusing on two categories of artificial intelligence (AI) technologies used in clinical trials. These are (1) analysis and feedback for improving colonoscopy quality and (2) detection of abnormalities. Our survey includes methods that use traditional machine learning algorithms on carefully designed hand-crafted features as well as recent deep-learning methods. Lastly, we present the gap between current state-of-the-art technology and desirable clinical features and conclude with future directions of endoscopic AI technology development that will bridge the current gap. Wallapak Tavanapong, Jung-Hwan Oh 0001, Michael Riegler 0001, Mohammed Khaleel, Bhuvan Mittal, Piet C. de Groen |
IEEE J. Biomed. Health Informatics | 3 |
| 2021 | Diagnosing Schizophrenia from Activity Records using Hidden Markov Model ParametersabstractThe diagnosis of Schizophrenia is mainly based on qualitative characteristics. With the usage of portable devices which measure activity of humans, the diagnosis of Schizophrenia can be enriched through quantitative features. The goal of this work is to classify between schizophrenic and non-schizophrenic subjects based on their measured activity over a certain amount of time. To do so, the periods in which a subject was resting or active were identified by the application of a Hidden Markov model (HMM). The trained model parameters of the HMM, such as the mean or variance of activity during the state of rest or activity, are used as classification features for a logistic regression model. Our results indicate that the features from the HMM are significant in classifying between schizophrenic and non-schizophrenic subjects. Moreover, the features outperform the features derived through other methods in literature in terms of goodness-of-fit and classification performance. Matthias Boeker, Michael Riegler 0001, Hugo Hammer, Pål Halvorsen, Ole Bernt Fasmer, Petter Jakobsen |
CBMS | 2 |
| 2021 | A self-learning teacher-student framework for gastrointestinal image classificationabstractWe present a semi-supervised teacher-student framework to improve classification performance on gastrointestinal image data. As labeled data is scarce in medical settings, this framework is built specifically to take advantage of vast amounts of unlabeled data. It consists of three main steps: (1) train a teacher model with labeled data, (2) use the teacher model to infer pseudo labels with unlabeled data, and (3) train a new and larger student model with a combination of labeled images and inferred pseudo labels. These three steps are repeated several times by treating the student as a teacher to relabel the unlabeled data and consequently train a new student. We demonstrate that our framework can classify both video capsule endoscopy (VCE) and standard endoscopy images. Our results indicate that our teacher-student framework can significantly increase the performance compared to traditional supervised-learning-based models, i.e., an overall increase in the F1-score of 4.7% for the Kvasir-Capsule VCE dataset and 3.2% for the HyperKvasir colonoscopy dataset. We believe that our framework can use more of the data collected at hospitals without the need for expert labels, contributing to overall better models for medical multimedia systems for automatic disease detection. Henrik L. Gjestang, Steven Alexander Hicks, Vajira Thambawita, Pål Halvorsen, Michael Riegler 0001 |
CBMS | 5 |
| 2021 | NanoNet: Real-Time Polyp Segmentation in Video Capsule Endoscopy and ColonoscopyabstractDeep learning in gastrointestinal endoscopy can assist to improve clinical performance and be helpful to assess lesions more accurately. To this extent, semantic segmentation methods that can perform automated real-time delineation of a region-of-interest, e.g., boundary identification of cancer or pre-cancerous lesions, can benefit both diagnosis and interventions. However, accurate and real-time segmentation of endoscopic images is extremely challenging due to its high operator dependence and high-definition image quality. To utilize automated methods in clinical settings, it is crucial to design lightweight models with low latency such that they can be integrated with low-end endoscope hardware devices. In this work, we propose NanoNet, a novel architecture for the segmentation of video capsule endoscopy and colonoscopy images. Our proposed architecture allows real-time performance and has higher segmentation accuracy compared to other more complex ones. We use video capsule endoscopy and standard colonoscopy datasets with polyps, and a dataset consisting of endoscopy biopsies and surgical instruments, to evaluate the effectiveness of our approach. Our experiments demonstrate the increased performance of our architecture in terms of a trade-off between model complexity, speed, model parameters, and metric performances. Moreover, the resulting models' size is relatively tiny, with only nearly 36,000 parameters compared to traditional deep learning approaches having millions of parameters. Debesh Jha, Nikhil Kumar Tomar, Sharib Ali, Michael Riegler 0001, Håvard D. Johansen, Dag Johansen, Thomas de Lange, Pål Halvorsen |
CBMS | 4 |
| 2021 | Automated Clipping of Soccer Events using Machine LearningabstractExtracting highlight clips from soccer matches requires tedious, time-consuming, and expensive manual labor. Human operators need to search for appropriate clipping points and trim away the unwanted scenes. In our work, we aim for an automated process for generating event highlights. In particular, we develop AI-models for scene boundary detection and logo detection. Using different datasets, we present two models that automatically find the appropriate time interval for goal event extraction. The models are evaluated quantitatively, and the results show that we find the logo and scene shifts with high accuracy. Our event clipping methodology is a potential building block for a larger, fully-automated sports broadcast production pipeline. Joakim O. Valand, Haris Kadragic, Steven Alexander Hicks, Vajira Thambawita, Cise Midoglu, Tomas Kupka, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
ISM | 8 |
| 2021 | ICDAR'21: Intelligent Cross-Data Analysis and RetrievalabstractCross-data analytics and retrieval have gained significant improvement recently. People can now extract more data insights precisely and quickly towards having many excellent applications serving human lives. Since people create multimedia and other types of data that reflect the diverse perspectives of human lives, these data are just pieces of the puzzle of the world's pictures. Hence, it is necessary to assembly all these pieces towards having a better solution for human-centered problems. Hence, the workshop welcomes those who work with multimedia and others and come from diverse research domains and disciplines to work on intelligent cross-data analytics and retrieval to bring a smart, sustainable society to human beings. The research domain can vary from well-being, disaster prevention and mitigation, mobility to food computing, to name a few. Minh-Son Dao, Michael Riegler 0001, Duc-Tien Dang-Nguyen, Cathal Gurrin, Minh-Triet Tran, Binh T. Nguyen 0001 |
ICMR | 2 |
| 2021 | HTAD: A Home-Tasks Activities Dataset with Wrist-Accelerometer and Audio Features
Enrique Garcia-Ceja, Vajira Thambawita, Steven Alexander Hicks, Debesh Jha, Petter Jakobsen, Hugo Hammer, Pål Halvorsen, Michael Riegler 0001 |
MMM (2) | 8 |
| 2021 | Kvasir-Instrument: Diagnostic and Therapeutic Tool Segmentation Dataset in Gastrointestinal Endoscopy
Debesh Jha, Sharib Ali, Krister Emanuelsen, Steven Alexander Hicks, Vajira Thambawita, Enrique Garcia-Ceja, Michael Riegler 0001, Thomas de Lange, Peter Thelin Schmidt, Håvard D. Johansen, Dag Johansen, Pål Halvorsen |
MMM (2) | 7 |
| 2021 | HYPERAKTIV: An Activity Dataset from Patients with Attention-Deficit/Hyperactivity Disorder (ADHD)abstractMachine learning research within healthcare frequently lacks the public data needed to be fully reproducible and comparable. Datasets are often restricted due to privacy concerns and legal requirements that come with patient-related data. Consequentially, many algorithms and models get published on the same topic without a standard benchmark to measure against. Therefore, this paper presents HYPERAKTIV, a public dataset containing health, activity, and heart rate data from patients diagnosed with attention deficit hyperactivity disorder, better known as ADHD. The dataset consists of data collected from 51 patients with ADHD and 52 clinical controls. In addition to the activity and heart rate data, we also include a series of patient attributes such as their age, sex, and information about their mental state, as well as output data from a computerized neuropsychological test. Together with the presented dataset, we also provide baseline experiments using traditional machine learning algorithms to predict ADHD based on the included activity data. We hope that this dataset can be used as a starting point for computer scientists who want to contribute to the field of mental health, and as a common benchmark for future work in ADHD analysis. Steven Alexander Hicks, Andrea Stautland, Ole Bernt Fasmer, Wenche Førland, Hugo Hammer, Pål Halvorsen, Kristin Mjeldheim, Ketil J. Oedegaard, Berge Osnes, Vigdis Elin Giæver Syrstad, Michael Riegler 0001, Petter Jakobsen |
MMSys | 11 |
| 2021 | Large scale "speedtest" experimentation in Mobile Broadband Networks
Cise Midoglu, Konstantinos Kousias, Özgü Alay, Andra Lutu, Antonios Argyriou, Michael Riegler 0001, Carsten Griwodz |
Comput. Networks | 6 |
| 2021 | A comprehensive analysis of classification methods in gastrointestinal endoscopy imagingabstractGastrointestinal (GI) endoscopy has been an active field of research motivated by the large number of highly lethal GI cancers. Early GI cancer precursors are often missed during the endoscopic surveillance. The high missed rate of such abnormalities during endoscopy is thus a critical bottleneck. Lack of attentiveness due to tiring procedures, and requirement of training are few contributing factors. An automatic GI disease classification system can help reduce such risks by flagging suspicious frames and lesions. GI endoscopy consists of several multi-organ surveillance, therefore, there is need to develop methods that can generalize to various endoscopic findings. In this realm, we present a comprehensive analysis of the Medico GI challenges: Medical Multimedia Task at MediaEval 2017, Medico Multimedia Task at MediaEval 2018, and BioMedia ACM MM Grand Challenge 2019. These challenges are initiative to set-up a benchmark for different computer vision methods applied to the multi-class endoscopic images and promote to build new approaches that could reliably be used in clinics. We report the performance of 21 participating teams over a period of three consecutive years and provide a detailed analysis of the methods used by the participants, highlighting the challenges and shortcomings of the current approaches and dissect their credibility for the use in clinical settings. Our analysis revealed that the participants achieved an improvement on maximum Mathew correlation coefficient (MCC) from 82.68% in 2017 to 93.98% in 2018 and 95.20% in 2019 challenges, and a significant increase in computational speed over consecutive years. Debesh Jha, Sharib Ali, Steven Alexander Hicks, Vajira Thambawita, Hanna Borgli, Pia H. Smedsrud, Thomas de Lange, Konstantin Pogorelov, Philipp Harzig, Minh-Triet Tran, Wenhua Meng, Trung-Hieu Hoang, Danielle Dias, Tobey H. Ko, Taruna Agrawal, Olga Ostroukhova, Zeshan Khan, Muhammad Atif Tahir, Yang Liu 0007, Mathias Kirkerød, Dag Johansen, Mathias Lux, Håvard D. Johansen, Michael Riegler 0001, Pål Halvorsen |
Medical Image Anal. | 26 |
| 2021 | Comparative validation of multi-instance instrument segmentation in endoscopy: Results of the ROBUST-MIS 2019 challengeabstractIntraoperative tracking of laparoscopic instruments is often a prerequisite for computer and robotic-assisted interventions. While numerous methods for detecting, segmenting and tracking of medical instruments based on endoscopic video images have been proposed in the literature, key limitations remain to be addressed: Firstly, robustness, that is, the reliable performance of state-of-the-art methods when run on challenging images (e.g. in the presence of blood, smoke or motion artifacts). Secondly, generalization; algorithms trained for a specific intervention in a specific hospital should generalize to other interventions or institutions. In an effort to promote solutions for these limitations, we organized the Robust Medical Instrument Segmentation (ROBUST-MIS) challenge as an international benchmarking competition with a specific focus on the robustness and generalization capabilities of algorithms. For the first time in the field of endoscopic image processing, our challenge included a task on binary segmentation and also addressed multi-instance detection and segmentation. The challenge was based on a surgical data set comprising 10,040 annotated images acquired from a total of 30 surgical procedures from three different types of surgery. The validation of the competing methods for the three tasks (binary segmentation, multi-instance detection and multi-instance segmentation) was performed in three different stages with an increasing domain gap between the training and the test data. The results confirm the initial hypothesis, namely that algorithm performance degrades with an increasing domain gap. While the average detection and segmentation quality of the best-performing algorithms is high, future research should concentrate on detection and segmentation of small, crossing, moving and transparent instrument(s) (parts). Tobias Roß, Annika Reinke, Peter M. Full, Martin Wagner 0001, Hannes Kenngott, Martin Apitz, Hellena Hempe, Diana Mîndroc-Filimon, Patrick Godau, Thuy Nuong Tran, Pierangela Bruno, Pablo Andrés Arbeláez, Guibin Bian, Sebastian Bodenstedt, Jon Lindström Bolmgren, Laura Bravo-Sánchez, Hua-Bin Chen, Cristina González, Pål Halvorsen, Pheng-Ann Heng, Enes Hosgor, Zeng-Guang Hou, Fabian Isensee, Debesh Jha, Tingting Jiang 0001, Yueming Jin, Kadir Kirtaç, Sabrina Kletz, Stefan Leger, Klaus H. Maier-Hein, Zhen-Liang Ni, Michael Riegler 0001, Klaus Schöffmann, Ruohua Shi, Stefanie Speidel, Michael Stenzel, Isabell Twick, Guotai Wang, Jiacheng Wang 0002, Liansheng Wang 0002, Lu Wang 0002, Yan-Jie Zhou, Lei Zhu 0003, Manuel Wiesenfarth, Annette Kopp-Schneider, Beat P. Müller-Stich, Lena Maier-Hein |
Medical Image Anal. | 34 |
| 2021 | A Comprehensive Study on Colorectal Polyp Segmentation With ResUNet++, Conditional Random Field and Test-Time AugmentationabstractColonoscopy is considered the gold standard for detection of colorectal cancer and its precursors. Existing examination methods are, however, hampered by high overall miss-rate, and many abnormalities are left undetected. Computer-Aided Diagnosis systems based on advanced machine learning algorithms are touted as a game-changer that can identify regions in the colon overlooked by the physicians during endoscopic examinations, and help detect and characterize lesions. In previous work, we have proposed the ResUNet++ architecture and demonstrated that it produces more efficient results compared with its counterparts U-Net and ResUNet. In this paper, we demonstrate that further improvements to the overall prediction performance of the ResUNet++ architecture can be achieved by using Conditional Random Field (CRF) and Test-Time Augmentation (TTA). We have performed extensive evaluations and validated the improvements using six publicly available datasets: Kvasir-SEG, CVC-ClinicDB, CVC-ColonDB, ETIS-Larib Polyp DB, ASU-Mayo Clinic Colonoscopy Video Database, and CVC-VideoClinicDB. Moreover, we compare our proposed architecture and resulting model with other state-of-the-art methods. To explore the generalization capability of ResUNet++ on different publicly available polyp datasets, so that it could be used in a real-world setting, we performed an extensive cross-dataset evaluation. The experimental results show that applying CRF and TTA improves the performance on various polyp segmentation datasets both on the same dataset and cross-dataset. To check the model's performance on difficult to detect polyps, we selected, with the help of an expert gastroenterologist, 196 sessile or flat polyps that are less than ten millimeters in size. This additional data has been made available as a subset of Kvasir-SEG. Our approaches showed good results for flat or sessile and smaller polyps, which are known to be one of the major reasons for high polyp miss-rates. This is one of the significant strengths of our work and indicates that our methods should be investigated further for use in clinical practice. Debesh Jha, Pia H. Smedsrud, Dag Johansen, Thomas de Lange, Håvard D. Johansen, Pål Halvorsen, Michael Riegler 0001 |
IEEE J. Biomed. Health Informatics | 7 |
| 2020 | PSYKOSE: A Motor Activity Database of Patients with SchizophreniaabstractUsing sensor data from devices such as smart-watches or mobile phones is very popular in both computer science and medical research. Such movement data can predict certain health states or performance outcomes. However, in order to increase reliability and replication of the research it is important to share data and results openly. In medicine, this is often difficult due to legal restrictions or to the fact that data collected from clinical trials is seen as very valuable and something that should be kept "in-house". In this paper, we therefore present PSYKOSE, a publicly shared dataset consisting of motor activity data collected from body sensors. The dataset contains data collected from patients with schizophrenia. Schizophrenia is a severe mental disorder characterized by psychotic symptoms like hallucinations and delusions, as well as symptoms of cognitive dysfunction and diminished motivation. In total, we have data from 22 patients with schizophrenia and 32 healthy control persons. For each person in the dataset, we provide sensor data collected over several days in a row. In addition to the sensor data, we also provide some demographic data and medical assessments during the observation period. The patients were assessed by medical experts from Haukeland University hospital. In addition to the data, we provide a baseline analysis and possible use-cases of the dataset. Petter Jakobsen, Enrique Garcia-Ceja, Lena Antonsen Stabell, Ketil J. Oedegaard, Jan Oystein Berle, Vajira Thambawita, Steven Alexander Hicks, Pål Halvorsen, Ole Bernt Fasmer, Michael Riegler 0001 |
CBMS | 10 |
| 2020 | DoubleU-Net: A Deep Convolutional Neural Network for Medical Image SegmentationabstractSemantic image segmentation is the process of labeling each pixel of an image with its corresponding class. An encoder-decoder based approach, like U-Net and its variants, is a popular strategy for solving medical image segmentation tasks. To improve the performance of U-Net on various segmentation tasks, we propose a novel architecture called DoubleU-Net, which is a combination of two U-Net architectures stacked on top of each other. The first U-Net uses a pre-trained VGG-19 as the encoder, which has already learned features from ImageNet and can be transferred to another task easily. To capture more semantic information efficiently, we added another U-Net at the bottom. We also adopt Atrous Spatial Pyramid Pooling (ASPP) to capture contextual information within the network. We have evaluated DoubleU-Net using four medical segmentation datasets, covering various imaging modalities such as colonoscopy, dermoscopy, and microscopy. Experiments on the MICCAI 2015 segmentation challenge, the CVC-ClinicDB, the 2018 Data Science Bowl challenge, and the Lesion boundary segmentation datasets demonstrate that the DoubleU-Net outperforms U-Net and the baseline models. Moreover, DoubleU-Net produces more accurate segmentation masks, especially in the case of the CVC-ClinicDB and MICCAI 2015 segmentation challenge datasets, which have challenging images such as smaller and flat polyps. These results show the improvement over the existing U-Net model. The encouraging results, produced on various medical image segmentation datasets, show that DoubleU-Net can be used as a strong baseline for both medical image segmentation and cross-dataset evaluation testing to measure the generalizability of Deep Learning (DL) models. Debesh Jha, Michael Riegler 0001, Dag Johansen, Pål Halvorsen, Håvard D. Johansen |
CBMS | 2 |
| 2020 | ImageCLEF 2020: Multimedia Retrieval in Lifelogging, Medical, Nature, and Internet Applications
Bogdan Ionescu, Henning Müller, Renaud Péteri, Duc-Tien Dang-Nguyen, Liting Zhou, Luca Piras 0001, Michael Riegler 0001, Pål Halvorsen, Minh-Triet Tran, Mathias Lux, Cathal Gurrin, Jon Chamberlain, Adrian F. Clark, Antonio C. de A. Campello Jr., Alba Garcia Seco de Herrera, Asma Ben Abacha, Vivek V. Datla, Sadid A. Hasan, Joey Liu, Dina Demner-Fushman, Obioma Pelka, Christoph M. Friedrich, Yashin Dicente Cid, Serge Kozlovski, Vitali Liauchuk, Vassili Kovalev, Raul Berari, Paul Brie, Dimitri Fichou, Mihai Dogariu, Liviu-Daniel Stefan, Mihai Gabriel Constantin |
ECIR (2) | 7 |
| 2020 | Vid2Pix - A Framework for Generating High-Quality Synthetic VideosabstractData is arguably the most important resource today as it fuels the algorithms powering services we use every day. However, in fields like medicine, publicly available datasets are few, and labeling medical datasets require tedious efforts from trained specialists. Generated synthetic data can be to future successful healthcare clinical intelligence. Here, we present a GAN-based video generator demonstrating promising results. Oda Olsen Nedrejord, Vajira Thambawita, Steven Alexander Hicks, Pål Halvorsen, Michael Riegler 0001 |
ISM | 5 |
| 2020 | Real-Time Detection of Events in Soccer Videos using 3D Convolutional Neural NetworksabstractIn this paper, we present an algorithm for automatically detecting events in soccer videos using 3D convolutional neural networks. The algorithm uses a sliding window approach to scan over a given video to detect events such as goals, yellow/red cards, and player substitutions. We test the method on three different datasets from SoccerNet, the Swedish Allsvenskan, and the Norwegian Eliteserien. Overall, the results show that we can detect events with high recall, low latency, and accurate time estimation. The trade-off is a slightly lower precision compared to the current state-of-the-art, which has higher latency and performs better when a less accurate time estimation can be accepted. In addition to the presented algorithm, we perform an extensive ablation study on how the different parts of the training pipeline affect the final results. Olav A. Norgård Rongved, Steven Alexander Hicks, Vajira Thambawita, Håkon Kvale Stensland, Evi Zouganeli, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
ISM | 7 |
| 2020 | ACM Multimedia BioMedia 2020 Grand Challenge OverviewabstractThe BioMedia 2020 ACM Multimedia Grand Challenge is the second in a series of competitions focusing on the use of multimedia for different medical use-cases. In this year's challenge, participants are asked to develop algorithms that automatically predict the quality of a given human semen sample using a combination of visual, patient-related, and laboratory-analysis-related data. Compared to last year's challenge, participants are provided with a fully multimodal dataset (videos, analysis data, study participant data) from the field of assisted human reproduction. The tasks encourage the use of the different modalities contained within the dataset and finding smart ways of how they may be combined to further improve prediction accuracy. For example, using only video data or combining video data and patient-related data. The ground truth was developed through a preliminary analysis done by medical experts following the World Health Organization's standard for semen quality assessment. The task lays the basis for automatic, real-time support systems for artificial reproduction. We hope that this challenge motivates multimedia researchers to explore more medical-related applications and use their vast knowledge to make a real impact on people's lives. Steven Alexander Hicks, Vajira Thambawita, Hugo Hammer, Trine B. Haugen, Jorunn M. Andersen, Oliwia Witczak, Pål Halvorsen, Michael Riegler 0001 |
ACM Multimedia | 8 |
| 2020 | Reproducibility Companion Paper: Selective Deep Convolutional Features for Image RetrievalabstractIn this companion paper, firstly, we briefly summarize the contributions of our main manuscript: Selective Deep Convolutional Features for Image Retrieval, published in ACM MultiMedia 2017. In addition, we provide detail instructions together with pre-configured MATLAB scripts which allow experiments to be executed and to reproduce the results reported in our main manuscript effortlessly. The source code is available at https://github.com/hnanhtuan/selectiveConvFeatures_ACMMM_reproducibility. Tuan Hoang, Thanh-Toan Do, Ngai-Man Cheung, Michael Riegler 0001, Jan Zahálka |
ACM Multimedia | 4 |
| 2020 | Reproducibility Companion Paper: Instance of Interest DetectionabstractTo support the replication of "Instance of Interest Detection", which was presented at MM'19, this companion paper provides the details of the artifacts. Instance of Interest Detection (IOID) aims to provide instance-level user interest modeling for image semantic description. In this paper, we explain the file structure of the source code and publish the details of our IOID dataset, which can be used to retrain the model with custom parameters. We also provide a program for component analysis to help other researchers to do experiments with alternative models that are not included in our experiments. Moreover, we provide a demo program for using our model easily. Fan Yu 0003, Tongwei Ren, Jinhui Tang 0001, Gangshan Wu, Jingjing Chen 0001, Michael Riegler 0001 |
ACM Multimedia | 8 |
| 2020 | Kvasir-SEG: A Segmented Polyp Dataset
Debesh Jha, Pia H. Smedsrud, Michael Riegler 0001, Pål Halvorsen, Thomas de Lange, Dag Johansen, Håvard D. Johansen |
MMM (2) | 3 |
| 2020 | Toadstool: a dataset for training emotional intelligent machines playing Super Mario BrosabstractGames are often defined as engines of experience, and they are heavily relying on emotions, they arouse in players. In this paper, we present a dataset called Toadstool as well as a reproducible methodology to extend on the dataset. The dataset consists of video, sensor, and demographic data collected from ten participants playing Super Mario Bros, an iconic and famous video game. The sensor data is collected through an Empatica E4 wristband, which provides high-quality measurements and is graded as a medical device. In addition to the dataset and the methodology for data collection, we present a set of baseline experiments which show that we can use video game frames together with the facial expressions to predict the blood volume pulse of the person playing Super Mario Bros. With the dataset and the collection methodology we aim to contribute to research on emotionally aware machine learning algorithms, focusing on reinforcement learning and multimodal data fusion. We believe that the presented dataset can be interesting for a manifold of researchers to explore exciting new interdisciplinary questions. Henrik Svoren, Vajira Thambawita, Pål Halvorsen, Petter Jakobsen, Enrique Garcia-Ceja, Farzan Majeed Noori, Hugo Hammer, Mathias Lux, Michael Riegler 0001, Steven Alexander Hicks |
MMSys | 9 |
| 2020 | PMData: a sports logging datasetabstractIn this paper, we present PMData: a dataset that combines traditional lifelogging data with sports-activity data. Our dataset enables the development of novel data analysis and machine-learning applications where, for instance, additional sports data is used to predict and analyze everyday developments, like a person's weight and sleep patterns; and applications where traditional lifelog data is used in a sports context to predict athletes' performance. PMData combines input from Fitbit Versa 2 smartwatch wristbands, the PMSys sports logging smartphone application, and Google forms. Logging data has been collected from 16 persons for five months. Our initial experiments show that novel analyses are possible, but there is still room for improvement. Vajira Thambawita, Steven Alexander Hicks, Hanna Borgli, Håkon Kvale Stensland, Debesh Jha, Martin Kristoffer Svensen, Svein Arne Pettersen, Dag Johansen, Håvard D. Johansen, Susann Dahl Pettersen, Simon Nordvang, Sigurd Pedersen, Anders T. Gjerdrum, Tor-Morten Grønli, Per Morten Fredriksen, Ragnhild Eg, Kjeld Hansen, Siri Fagernes, Christine Claudi, Andreas Biørn-Hansen, Duc-Tien Dang-Nguyen, Tomas Kupka, Hugo Hammer, Ramesh Jain 0001, Michael Riegler 0001, Pål Halvorsen |
MMSys | 25 |
| 2020 | LightLayers: Parameter Efficient Dense and Convolutional Layers for Image Classification
Debesh Jha, Anis Yazidi, Michael Riegler 0001, Dag Johansen, Håvard D. Johansen, Pål Halvorsen |
PDCAT | 3 |
| 2020 | An Extensive Study on Cross-Dataset Bias and Evaluation Metrics Interpretation for Machine Learning Applied to Gastrointestinal Tract Abnormality ClassificationabstractPrecise and efficient automated identification of gastrointestinal (GI) tract diseases can help doctors treat more patients and improve the rate of disease detection and identification. Currently, automatic analysis of diseases in the GI tract is a hot topic in both computer science and medical-related journals. Nevertheless, the evaluation of such an automatic analysis is often incomplete or simply wrong. Algorithms are often only tested on small and biased datasets, and cross-dataset evaluations are rarely performed. A clear understanding of evaluation metrics and machine learning models with cross datasets is crucial to bring research in the field to a new quality level. Toward this goal, we present comprehensive evaluations of five distinct machine learning models using global features and deep neural networks that can classify 16 different key types of GI tract conditions, including pathological findings, anatomical landmarks, polyp removal conditions, and normal findings from images captured by common GI tract examination instruments. In our evaluation, we introduce performance hexagons using six performance metrics, such as recall, precision, specificity, accuracy, F1-score, and the Matthews correlation coefficient to demonstrate how to determine the real capabilities of models rather than evaluating them shallowly. Furthermore, we perform cross-dataset evaluations using different datasets for training and testing. With these cross-dataset evaluations, we demonstrate the challenge of actually building a generalizable model that could be used across different hospitals. Our experiments clearly show that more sophisticated performance metrics and evaluation methods need to be applied to get reliable models rather than depending on evaluations of the splits of the same dataset—that is, the performance metrics should always be interpreted together rather than relying on a single metric. Vajira Thambawita, Debesh Jha, Hugo Hammer, Håvard D. Johansen, Dag Johansen, Pål Halvorsen, Michael Riegler 0001 |
ACM Trans. Comput. Heal. | 7 |
| 2020 | Human Activity Recognition from Multiple Sensors Data Using Multi-fusion Representations and CNNsabstractWith the emerging interest in the ubiquitous sensing field, it has become possible to build assistive technologies for persons during their daily life activities to provide personalized feedback and services. For instance, it is possible to detect an individual’s behavioral pattern (e.g., physical activity, location, and mood) by using sensors embedded in smart-watches and smartphones. The multi-sensor environments also come with some challenges, such as how to fuse and combine different sources of data. In this article, we explore several methods of fusion for multi-representations of data from sensors. Furthermore, multiple representations of sensor data were generated and then fused using data-level, feature-level , and decision-level fusions . The presented methods were evaluated using three publicly available human activity recognition (HAR) datasets. The presented approaches utilize Deep Convolutional Neural Networks (CNNs). A generic architecture for fusion of different sensors is proposed. The proposed method shows promising performance, with the best results reaching an overall accuracy of 98.4% for the Context-Awareness via Wrist-Worn Motion Sensors (HANDY) dataset and 98.7% for the Wireless Sensor Data Mining (WISDM version 1.1) dataset. Both results outperform previous approaches. Farzan Majeed Noori, Michael Riegler 0001, Md. Zia Uddin, Jim Tørresen |
ACM Trans. Multim. Comput. Commun. Appl. | 2 |
| 2020 | User-adaptive models for activity and emotion recognition using deep transfer learning and data augmentation
Enrique Garcia-Ceja, Michael Riegler 0001, Anders K. Kvernberg, Jim Tørresen |
User Model. User Adapt. Interact. | 2 |
| 2019 | Real-time Analysis of Physical Performance Parameters in Elite SoccerabstractTechnology is having vast impact on the sports industry, and in particular soccer. All over the world, soccer teams are adapting digital information systems to quantify performance metrics. The goal is to assess strengths and weaknesses of individual players, training regimes, and play strategies; to improve performance and win games. However, most existing methods rely on post-game analytic. This limits coaches to review games in retrospect without any means to do changes during sessions. In collaboration with an elite soccer club, we have developed Metrix which is a computerized toolkit for coaches to perform realtime monitoring and analysis of the players' performance. Using sensor technology to track movement, performance parameters are instantly available to coaches through a mobile phone client. Metrix provides coaches with a toolkit to individualize training load to different playing positions on the field, or to the player himself. Our results show that Metrix is able to quantify player performance and propagate it to coaches in real-time during a match or practice, i.e., latency is below 100 ms on the field. In our initial user evaluation, the coaches express that this is a valuable asset in day-to-day work. Kim Andreassen, Dag Johansen, Håvard D. Johansen, Ivan Baptista, Svein Arne Pettersen, Michael Riegler 0001, Pål Halvorsen |
CBMI | 6 |
| 2019 | Saga: An Open Source Platform for Training Machine Learning Models and Community-driven Sharing of TechniquesabstractWith the increasing popularity of machine learning in areas such as multimedia indexing and social media analysis, comes an increasing number of tools for developing and training the machine learning models. These tools assist in the selection and optimization of hyperparameters, but the user becomes locked into the platform's built-in solutions. Therefore, this demo presents an open-source, community-driven platform for sharing machine learning models, training techniques, and datasets. The platform, called Saga, provides a machine learning training pipeline such as those found in machine learning services provided by cloud providers. However, Saga also provides a store where users can upload and share their machine learning training methods. Additionally, the store allows users to rate and comment on other users' uploaded methods, as well as download and run them without any additional setup. In our demo, we will run a scenario where a user wants to train an image classifier using Saga. The demonstration will involve downloading methods from the store and displaying the pipeline provided by the Saga platform. Rune Johan Borgli, Håkon Kvale Stensland, Pål Halvorsen, Michael Riegler 0001 |
CBMI | 4 |
| 2019 | THREAT: A Large Annotated Corpus for Detection of Violent ThreatsabstractUnderstanding, detecting, moderating and in extreme cases deleting hateful comments in online discussions and social media are well-known challenges. In this paper we present a dataset consisting of a total of around 30 000 sentences from around 10 000 YouTube comments. Each sentence is manually annotated as either being a violent threat or not. Violent threats is the most extreme form of hateful communication and is of particular importance from an online radicalization and national security perspective. This is the first publicly available dataset with such an annotation. The dataset can further be useful to develop automatic moderation tools or may even be useful from a social science perspective for analyzing the characteristics of online threats and how hateful discussions evolve. Hugo Hammer, Michael Riegler 0001, Lilja Øvrelid, Erik Velldal |
CBMI | 2 |
| 2019 | Heart Rate Prediction from Head Movement during Virtual Reality Treatment for Social AnxietyabstractNowadays, virtual reality exposure therapy (VRET) is suggested as a way to treat social anxiety disorder (SAD), including the more specific fear of public speaking (FoPs). The major advantage of using VRET is that the virtual environment represents something in between in vitro and in vivo exposure, and therefore, lower the threshold for engaging in exposure tasks. In this paper, we present a VR system for addressing public speaking anxiety. Furthermore, wireless wristband was worn to detect the heartbeat of the participant in real-time and head movement data were collected from the VR headset. In initial experiments, we use the movement from the VR headset to predict heart rate with the goal of being able to get heart rate from VR equipment without the need for additional equipment allowing larger follow up studies. Farzan Majeed Noori, Smiti Kahlon, Philip Lindner, Tine Nordgreen, Jim Tørresen, Michael Riegler 0001 |
CBMI | 6 |
| 2019 | Semantic Analysis of Soccer News for Automatic Game Event ClassificationabstractWe are today overwhelmed with information, of which an important part is news. Sports news, in particular, has become very popular, where soccer makes up a big part of this coverage. For sports fans, it can be a time consuming and tedious to keep up with the news that they really care about. In this paper, we present different machine learning methods applied to soccer news from a Norwegian newspaper and a TV station's news site to summarize the content in a short and digestible manner. We present a system to collect, index, label, analyze, and present the collected news articles based on the content. We perform a thorough comparison between deep learning and traditional machine learning algorithms on text classification. Furthermore, we present a dataset of soccer news which was collected from two different Norwegian news sites and shared online. Aanund Jupskås Nordskog, Pål Halvorsen, Steven Alexander Hicks, Håkon Kvale Stensland, Hugo Hammer, Dag Johansen, Michael Riegler 0001 |
CBMI | 7 |
| 2019 | GANEx: A complete pipeline of training, inference and benchmarking GAN experimentsabstractDeep learning (DL) is one of the standard methods in the field of multimedia research to perform data classification, detection, segmentation and generation. Within DL, generative adversarial networks (GANs) represents a new and highly popular branch of methods. GANs have the capability to generate, from random noise or conditional input, new data realizations within the dataset population. While generation is popular and highly useful in itself, GANs can also be useful to improve supervised DL. GAN-based approaches can, for example, perform segmentation or create synthetic data for training other DL models. The latter one is especially interesting in domains where not much training data exists such as medical multimedia. In this respect, performing a series of experiments involving GANs can be very time consuming due to the lack of tools that support the whole pipeline such as structured training, testing and tracking of different architectures and configurations. Moreover, the success of generative models is highly dependent on hyper-parameter optimization and statistical analysis in the design and fine-tuning stages. In this paper, we present a new tool called GANEx for making the whole pipeline of training, inference and benchmarking GANs faster, more efficient and more structured. The tool consists of a special library called FastGAN which allows designing generative models very fast. Moreover, GANEx has a graphical user interface to support structured experimenting, quick hyper-parameter configurations and output analysis. The presented tool is not limited to a specific DL framework and can be therefore even used to compare the performance of cross frameworks. Vajira Thambawita, Hugo Hammer, Michael Riegler 0001, Pål Halvorsen |
CBMI | 3 |
| 2019 | Predicting Peek Readiness-to-Train of Soccer Players Using Long Short-Term Memory Recurrent Neural NetworksabstractWe are witnessing the emergence of a myriad of hardware and software systems that quantifies sport and physical activities. These are frequently touted as game changers and important for future sport developments. The vast amount of generated data is often visualized in graphs and dashboards, for use by coaches and other sports professionals to make decisions on training and match strategies. Modern machine-learning methods has the potential to further fuel this process by deriving useful insights that are not easily observable in the raw data streams. This paper tackles the problem of deriving peaks in soccer players' ability to perform from subjective self-reported wellness data collected using the PMSys system. For this, we train a long short-term memory recurrent neural network model using data from two professional Norwegian soccer teams. We show that our model can predict performance peaks in most scenarios with a precision and recall of at least 90%. Equipped with such insight, coaches and trainers can better plan individual and team training sessions, and perhaps avoid over training and injuries. Theodor Wiik, Håvard D. Johansen, Svein Arne Pettersen, Ivan Baptista, Tomas Kupka, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
CBMI | 7 |
| 2019 | Performance of Data Enhancements and Training Optimization for Neural Network: A Polyp Detection Case StudyabstractDeep learning using neural networks is becoming more and more popular. It is frequently used in areas like video analysis, image retrieval, traffic forecast and speech recognition. In this respect, the learning and training process usually requires a lot of data. However, in many areas, data is scarce which is definitely the case in our medical application scenario, i.e., polyp detection in the gastrointestinal tract. Here, colorectal cancer is on the list of most common cancer types, and often, the cancer arises from benign, adenomatous polyps containing dysplastic cells. Detection and removal of polyps can therefore prevent the development of cancer. % Due to high cost, time consumption, patient discomfort and in-accuracy of existing procedures, researchers have started to explore systems for automatic polyp detection to assist and automate current examination procedures. Following the current gained traction for neural networks, and the typical lack of medical data, we explore how data enhancements affect the training and evaluation of the networks in terms of polyp detection accuracy and particularly if it can be used to increase the detection rate. We also experiment with how various training techniques can be used to increase performance. Our experimental results show how data enhancement and training optimization can be used to increase different aspects of the performance, but we also point out mechanisms that have no, and even a negative, effect. Fredrik Lund Henriksen, Rune Jensen, Håkon Kvale Stensland, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
CBMS | 5 |
| 2019 | ImageCLEF 2019: Multimedia Retrieval in Lifelogging, Medical, Nature, and Security Applications
Bogdan Ionescu, Henning Müller, Renaud Péteri, Duc-Tien Dang-Nguyen, Luca Piras 0001, Michael Riegler 0001, Minh-Triet Tran, Mathias Lux, Cathal Gurrin, Yashin Dicente Cid, Vitali Liauchuk, Vassili Kovalev, Asma Ben Abacha, Sadid A. Hasan, Vivek V. Datla, Joey Liu, Dina Demner-Fushman, Obioma Pelka, Christoph M. Friedrich, Jon Chamberlain, Adrian F. Clark, Alba Garcia Seco de Herrera, Narciso García, Ergina Kavallieratou, Carlos R. del-Blanco, Carlos Cuevas, Nikos Vasilopoulos, Konstantinos Karampidis |
ECIR (2) | 6 |
| 2019 | Fusion of Multiple Representations Extracted from a Single Sensor's Data for Activity Recognition Using CNNsabstractWith the emerging ubiquitous sensing field, it has become possible to build assistive technologies for persons during their daily life activities to provide personalized feedback and services. For instance, it is possible to detect an individual's behavioral information (e.g. physical activity, location, and mood) by using sensors embedded in smartwatches and smartphones. To detect human's daily life activities, accelerometers have been widely used in wearable devices. In the current research, usually a single data representation is used, i.e., either image or feature vector representations. In this paper, a novel method is proposed to address two key aspects for the future development of robust deep learning methods for Human Activity Recognition (HAR): (1) multiple representations of a single sensor's data and (2) fusion of these multiple representations. The presented method utilizes Deep Convolutional Neural Networks (CNNs) and was evaluated using a publicly available HAR dataset. The proposed method showed promising performance, with the best result reaching an overall accuracy of 0.97, which outperforms current conventional approaches. Farzan Majeed Noori, Enrique Garcia-Ceja, Md. Zia Uddin, Michael Riegler 0001, Jim Tørresen |
IJCNN | 4 |
| 2019 | A Web-Based Software for Training and Quality Assessment in the Image Analysis Workflow for Cardiac T1 Mapping MRIabstractMedical practice makes significant use of imaging scans such as Ultrasound or Magnetic Resonance Imaging as a diagnostic tool. They are used in the visual inspection or quantification of medical parameters computed from the images in post-processing. However, the value of such parameters depends much on the user's variability, device, and algorithmic differences. In this paper, we focus on quantifying the variability due to the human factor, which can be primarily addressed by the structured training of a human operator. We focus on a specific emerging cardiovascular MRI methodology, the T1 mapping, that has proven useful to identify a range of pathological alterations of the myocardial tissue structure. Training, especially in emerging techniques, is typically not standardized, varying dramatically across medical centers and research teams. Additionally, training assessment is mostly based on qualitative approaches. Our work aims to provide a software tool combining traditional clinical metrics and convolutional neural networks to aid the training process by gathering contours from multiple trainees, quantifying discrepancy from local gold standard or standardized guidelines, classifying trainees output based on critical parameters that affect contours variability. Edvarda Eriksen, Steven Alexander Hicks, Michael Riegler 0001, Pål Halvorsen, Valentina Carapella |
ISM | 3 |
| 2019 | ResUNet++: An Advanced Architecture for Medical Image SegmentationabstractAccurate computer-aided polyp detection and segmentation during colonoscopy examinations can help endoscopists resect abnormal tissue and thereby decrease chances of polyps growing into cancer. Towards developing a fully automated model for pixel-wise polyp segmentation, we propose ResUNet++, which is an improved ResUNet architecture for colonoscopic image segmentation. Our experimental evaluations show that the suggested architecture produces good segmentation results on publicly available datasets. Furthermore, ResUNet++ significantly outperforms U-Net and ResUNet, two key state-of-the-art deep learning architectures, by achieving high evaluation scores with a dice coefficient of 81.33%, and a mean Intersection over Union (mIoU) of 79.27% for the Kvasir-SEG dataset and a dice coefficient of 79.55%, and a mIoU of 79.62% with CVC-612 dataset. Debesh Jha, Pia H. Smedsrud, Michael Riegler 0001, Dag Johansen, Thomas de Lange, Pål Halvorsen, Håvard D. Johansen |
ISM | 3 |
| 2019 | Using Mr. MAPP for Lower Limb Phantom Pain ManagementabstractPhantom pain is a chronic pain that is experienced as a vivid sensation stemming from the missing limb. From traditional mirror box to virtual reality-based approaches, a wide spectrum of treatments using mimic feedback of the amputated limb have been developed for alleviating phantom limb pain. In our previous work, Mixed reality-based framework for MAnaging Phantom Pain (Mr.MAPP) was presented and used to generate a virtual phantom upper limb, in real time, to manage the phantom pain. However, amputation of the lower limb is more common than that of the upper limb. Hence, in this paper, on top of demonstrating the reproducibility of the Mr.MAPP framework for upper limb, we extend it to manage lower limb phantom pain as well. Unlike an upper limb amputee, a patient with lower limb amputated is constrained to perform the training procedure in a sitting posture. Accordingly, virtual training games are designed for lower limb exercises with sitting posture such as knee flexion and extension, ankle dorsiflexion and tandem coordinated movement. Finally, the technical details of the system setup for playing the training games are introduced. Kanchan Bahirat, Yu-Yen Chung, Thiru Annaswamy, Gargi Raval, Kevin Desai, B. Prabhakaran 0001, Michael Riegler 0001 |
ACM Multimedia | 7 |
| 2019 | Medical Multimedia Systems and ApplicationsabstractIn recent years, we have observed a rise of interest in the multimedia community towards research topics related to health. It can be observed that this goes into two interesting directions. One is personal health with a larger focus on well-being and everyday healthy living. The other direction focuses more on multimedia challenges within the health-care systems, for example, how can multimedia content produced in hospitals be used efficiently but also on the user perspective of patients and health-care personal. Challenges and requirements in this interesting and challenging direction are similar to classic multimedia research, but with some additional pitfalls and challenges. This tutorial aims to give a general introduction to the research area; to provide an overview of specific requirements, pitfalls and challenges; to discuss existing and possible future work; and to elaborate on how machine learning approaches can help in multimedia-related challenges to improve the health-care quality for patients and support medical experts in their daily work. Pål Halvorsen, Michael Riegler 0001, Klaus Schöffmann |
ACM Multimedia | 2 |
| 2019 | ACM Multimedia BioMedia 2019 Grand Challenge OverviewabstractThe BioMedia 2019 ACM Multimedia Grand Challenge is the first in a series of competitions focusing on the use of multimedia for different medical use-cases. In this year's challenge, the participants are asked to develop efficient algorithms which automatically detect a variety of findings commonly identified in the gastrointestinal (GI) tract (a part of the human digestive system). The purpose of this task is to develop methods to aid medical doctors performing routine endoscopy inspections of the GI tract. In this paper, we give a detailed description of the four different tasks of this year's challenge, present the datasets used for training and testing, and discuss how each submission is evaluated both qualitatively and quantitatively. Steven Alexander Hicks, Michael Riegler 0001, Pia H. Smedsrud, Trine B. Haugen, Kristin Ranheim Randel, Konstantin Pogorelov, Håkon Kvale Stensland, Duc-Tien Dang-Nguyen, Mathias Lux, Andreas Petlund, Thomas de Lange, Peter Thelin Schmidt, Pål Halvorsen |
ACM Multimedia | 2 |
| 2019 | VISEM: a multimodal video dataset of human spermatozoaabstractReal multimedia datasets that contain more than just images or text are rare. Even more so are open multimedia datasets in medicine. Often, clinically related datasets only consist of image or videos. In this paper, we present a dataset that is novel in two ways. Firstly, it is a multi-modal dataset containing different data sources such as videos, biological analysis data, and participant data. Secondly, it is the first dataset of that kind in the field of human reproduction. It consists of anonymized data from 85 different participants. We hope this dataset paper will inspire people to apply their knowledge in this important field, generate shareable results in the domain, and ultimately improve human infertility investigation and treatment. Trine B. Haugen, Steven Alexander Hicks, Jorunn M. Andersen, Oliwia Witczak, Hugo Hammer, Rune Johan Borgli, Pål Halvorsen, Michael Riegler 0001 |
MMSys | 8 |
| 2019 | Estimating Downlink Throughput from End-user Measurements in Mobile Broadband NetworksabstractIn recent years, Downlink (DL) throughput estimation in Mobile Broadband (MBB) networks has gained immense popularity and it is expected to become a vital component of the upcoming fifth generation (5G) systems. Plentiful adaptive video streaming algorithms greatly rely on accurate DL throughput predictions to adapt their mechanisms and ensure high Quality of Service (QoS) to the end-users. Thus far, conventional DL throughput estimation approaches, also known as speed tests, require an extensive exchange of TCP traffic over the network for an allocated time duration. While such tools appear to deliver trustworthy results, they turn out to be inefficient when mobile subscriptions with limited data plans are engaged. In this paper, we propose a supervised Machine Learning (ML) solution for DL throughput estimation that aims at delivering highly accurate predictions while significantly limiting the over-the-air data consumption. We capture the network performance metrics by exploring both crowdsourced and controlled testing methodologies. We leverage RTR-NetTest, a platform of broadband measurements provided by the Austrian Regulatory Authority for Broadcasting and Telecommunications (RTR), and MONROE-NetTest, its counterpart wrapper built as an Experiment as a Service (EaaS) on top of Measuring Mobile Broadband Networks in Europe (MONROE). Results reveal that our solution can achieve a 39.7% reduction in terms of data consumption while delivering a Median Absolute Percentage Error (MdAPE) of 5.55%. We further show that accuracy can be traded-off, for example, a significant data consumption reduction of 95.15% can be achieved for a MdAPE of 20%. Konstantinos Kousias, Özgü Alay, Antonios Argyriou, Andra Lutu, Michael Riegler 0001 |
WOWMOM | 5 |
| 2019 | Social media and satellites - Disaster event detection, linking and summarization
Kashif Ahmad, Konstantin Pogorelov, Michael Riegler 0001, Nicola Conci, Pål Halvorsen |
Multim. Tools Appl. | 3 |
| 2019 | Natural disasters detection in social media and satellite imagery: a survey
Naina Said, Kashif Ahmad, Michael Riegler 0001, Konstantin Pogorelov, Laiq Hassan, Nasir Ahmad, Nicola Conci |
Multim. Tools Appl. | 3 |
| 2019 | Automatic detection of passable roads after floods in remote sensed and social media data
Kashif Ahmad, Konstantin Pogorelov, Michael Riegler 0001, Olga Ostroukhova, Pål Halvorsen, Nicola Conci, Rozenn Dahyot |
Signal Process. Image Commun. | 3 |
| 2018 | Motor Activity Based Classification of Depression in Unipolar and Bipolar PatientsabstractWearable sensors measuring different parts of people's activity are a common technology nowadays. Data created using these devices holds a lot of potential besides measuring the quantity of daily steps or calories burned, since continuous recordings of heart rate and activity levels usually are collected. Furthermore, there is an increasing awareness in the field of psychiatry on how these activity data relates to various mental health issues such as changes in mood, personality, inability to cope with daily problems or stress and withdrawal from friends and activities. In this paper we present the analysis of a unique dataset containing sensor data collected from patients suffering from depression. The dataset contains motor activity recordings of 23 unipolar and bipolar depressed patients and 32 healthy controls. We apply machine learning to classify patients into depressed and nondepressed. For evaluation of the algorithms, leave one patient out validation is performed. The best results achieved are an F1 score of 0.73 and a MCC of 0.44. The overall findings show that sensor data contains information that can be used to determine the depression status of a person. Enrique Garcia-Ceja, Michael Riegler 0001, Petter Jakobsen, Jim Tørresen, Tine Nordgreen, Ketil J. Oedegaard, Ole Bernt Fasmer |
CBMS | 2 |
| 2018 | Dissecting Deep Neural Networks for Better Medical Image Classification and Classification UnderstandingabstractNeural networks, in the context of deep learning, show much promise in becoming an important tool with the purpose assisting medical doctors in disease detection during patient examinations. However, the current state of deep learning is something of a "black box", making it very difficult to understand what internal processes lead to a given result. This is not only true for non-technical users but among experts as well. This lack of understanding has led to hesitation in the implementation of these methods among mission-critical fields, with many putting interpretability in front of actual performance. Motivated by increasing the acceptance and trust of these methods, and to make qualified decisions, we present a system that allows for the partial opening of this black box. This includes an investigation on what the neural network sees when making a prediction, to both, improve algorithmic understanding, and to gain intuition into what pre-processing steps may lead to better image classification performance. Furthermore, a significant part of a medical expert's time is spent preparing reports after medical examinations, and if we already have a system for dissecting the analysis done by the network, the same tool can be used for automatic examination documentation through content suggestions. In this paper, we present a system that can look into the layers of a deep neural network and present the network's decision in a way that that medical doctors may understand. Furthermore, we present and discuss how this information can possibly be used for automatic reporting. Our initial results are very promising. Steven Alexander Hicks, Michael Riegler 0001, Konstantin Pogorelov, Kim V. Anonsen, Thomas de Lange, Dag Johansen, Mattis Jeppsson, Kristin Ranheim Randel, Sigrun Losada Eskeland, Pål Halvorsen |
CBMS | 2 |
| 2018 | Deep Learning and Hand-Crafted Feature Based Approaches for Polyp Detection in Medical VideosabstractVideo analysis including classification, segmentation or tagging is one of the most challenging but also interesting topics multimedia research currently try to tackle. This is often related to videos from surveillance cameras or social media. In the last years, also medical institutions produce more and more video and image content. Some areas of medical image analysis, like radiology or brain scans, are well covered, but there is a much broader potential of medical multimedia content analysis. For example, in colonoscopy, 20% of polyps are missed or incompletely removed on average. Thus, automatic detection to support medical experts can be useful. In this paper, we present and evaluate several machine learning-based approaches for real-time polyp detection for live colonoscopy. We propose pixel-wise localization and frame-wise detection methods which include both handcrafted and deep learning based approaches. The experimental results demonstrate the capability of analyzing multimedia content in real clinical settings, the possible improvements in the work flow and the potential improved detection rates for medical experts. Konstantin Pogorelov, Olga Ostroukhova, Mattis Jeppsson, Håvard Espeland, Carsten Griwodz, Thomas de Lange, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
CBMS | 8 |
| 2018 | Tradeoffs Using Binary and Multiclass Neural Network Classification for Medical Multidisease DetectionabstractThe interest in neural networks has increased significantly, and the application of this type of machine learning is vast, ranging from natural image classification to medical image segmentation. However, many users of neural networks tend to use them as a black box tool. They do not access all of the possible variations, nor take into account the respective classification accuracies and costs. In our work, we focus on multiclass image classification, and in this research, we shed light on the trade-offs between systems using a single multiclass classification and multiple binary classifiers, respectively. We have tested these classifiers on several modern neural network architectures, including DenseNet, Inception v3, Inception ResNet v2, Xception, NASNet and MobileNet. We have compared several aspects of the performance of these architectures during training and testing using both classification styles in terms of classification speed and several classification accuracy metrics. Here, we present the results from experiments on a total of 99 networks: 11 multiclass and 88 individual binary networks, for an 8-class classification of medical images. In short, using multiple binary classification networks resulted in a more robust model (less variance) for the task at hand. However, on average, such a multi-network style performed the classification 7.6 times slower compared to a single network multiclass implementation. These collective findings show that both approaches can be applied to modern neural network structures. Several binary networks can often give more robust and increased classification accuracy, but at the cost of classification speed and resources consumption. Tor Jan Derek Berstad, Michael Riegler 0001, Håvard Espeland, Thomas de Lange, Pia H. Smedsrud, Konstantin Pogorelov, Håkon Kvale Stensland, Pål Halvorsen |
ISM | 2 |
| 2018 | Efficient Live and on-Demand Tiled HEVC 360 VR Video StreamingabstractWith 360° panorama video technology becoming commonplace, the need for efficient streaming methods for such videos arises. We go beyond the existing on-demand solutions and present a live streaming system which strikes a trade-off between bandwidth usage and the video quality in the user’s field-of-view. We have created an architecture that combines RTP and DASH to deliver 360° VR content to a Huawei set-top-box and a Samsung Galaxy S7. Our system multiplexes a single HEVC hardware decoder to provide faster quality switching than at the traditional GOP boundaries. We demonstrate the performance and illustrate the trade-offs through real-world experiments where we can report comparable bandwidth savings to existing on-demand approaches, but with faster quality switches when the field-of-view changes. Mattis Jeppsson, Håvard Espeland, Tomas Kupka, Ragnar Langseth, Andreas Petlund, Peng Qiaoqiao, Chuansong Xue, Konstantin Pogorelov, Michael Riegler 0001, Dag Johansen, Carsten Griwodz, Pål Halvorsen |
ISM | 9 |
| 2018 | Challenges and Opportunities within Personal Life ArchivesabstractNowadays, almost everyone holds some form or other of a personal life archive. Automatically maintaining such an archive is an activity that is becoming increasingly common, however without automatic support the users will quickly be overwhelmed by the volume of data and will miss out on the potential benefits that lifelogs provide. In this paper we give an overview of the current status of lifelog research and propose a concept for exploring these archives. We motivate the need for new methodologies for indexing data, organizing content and supporting information access. Finally we will describe challenges to be addressed and give an overview of initial steps that have to be taken, to address the challenges of organising and searching personal life archives. Duc-Tien Dang-Nguyen, Michael Riegler 0001, Liting Zhou, Cathal Gurrin |
ICMR | 2 |
| 2018 | The Importance of Medical MultimediaabstractMultimedia research is becoming more and more important for the medical domain, where an increasing number of videos and images are integrated in the daily routine of surgical and diagnostic work. While the collection of medical multimedia data is not an issue, appropriate tools for efficient use of this data are missing. This includes management and inspection of the data, visual analytics, as well as learning relevant semantics and using recognition results for optimizing surgical and diagnostic processes. The characteristics and requirements in this interesting but challenging field are different than the ones in classic multimedia domains. Therefore, this tutorial gives a general introduction to the field, provides a broad overview of specific requirements and challenges, discusses existing work and open challenges, and elaborates in detail how machine learning approaches can help in multimedia-related fields to improve the performance of surgeons/clinicians. Michael Riegler 0001, Pål Halvorsen, Bernd Münzer, Klaus Schöffmann |
ACM Multimedia | 1 |
| 2018 | Depresjon: a motor activity database of depression episodes in unipolar and bipolar patientsabstractWearable sensors measuring different parts of people's activity are a common technology nowadays. In research, data collected using these devices also draws attention. Nevertheless, datasets containing sensor data in the field of medicine are rare. Often, data is non-public and only results are published. This makes it hard for other researchers to reproduce and compare results or even collaborate. In this paper we present a unique dataset containing sensor data collected from patients suffering from depression. The dataset contains motor activity recordings of 23 unipolar and bipolar depressed patients and 32 healthy controls. For each patient we provide sensor data over several days of continuous measuring and also some demographic data. The severity of the patients' depressive state was labeled using ratings done by medical experts on the Montgomery-Asberg Depression Rating Scale (MADRS). In this respect, the here presented dataset can be useful to explore and understand the association between depression and motor activity better. By making this dataset available, we invite and enable interested researchers the possibility to tackle this challenging and important societal problem. Enrique Garcia-Ceja, Michael Riegler 0001, Petter Jakobsen, Jim Tørresen, Tine Nordgreen, Ketil J. Oedegaard, Ole Bernt Fasmer |
MMSys | 2 |
| 2018 | Mimir: an automatic reporting and reasoning system for deep learning based analysis in the medical domainabstractAutomatic detection of diseases is a growing field of interest, and machine learning in form of deep learning neural networks are frequently explored as a potential tool for the medical video analysis. To both improve the "black box"-understanding and assist in the administrative duties of writing an examination report, we release an automated multimedia reporting software dissecting the neural network to learn the intermediate analysis steps, i.e., we are adding a new level of understanding and explainability by looking into the deep learning algorithms decision processes. The presented open-source software can be used for easy retrieval and reuse of data for automatic report generation, comparisons, teaching and research. As an example, we use live colonoscopy as a use case which is the gold standard examination of the large bowel, commonly performed for clinical and screening purposes. The added information has potentially a large value, and reuse of the data for the automatic reporting may potentially save the doctors large amounts of time. Steven Alexander Hicks, Sigrun Losada Eskeland, Mathias Lux, Thomas de Lange, Kristin Ranheim Randel, Mattis Jeppsson, Konstantin Pogorelov, Pål Halvorsen, Michael Riegler 0001 |
MMSys | 9 |
| 2018 | Comprehensible reasoning and automated reporting of medical examinations based on deep learning analysisabstractIn the future, medical doctors will to an increasing degree be assisted by deep learning neural networks for disease detection during examinations of patients. In order to make qualified decisions, the black box of deep learning must be opened to increase the understanding of the reasoning behind the decision of the machine learning system. Furthermore, preparing reports after the examinations is a significant part of a doctors work-day, but if we already have a system dissecting the neural network for understanding, the same tool can be used for automatic report generation. In this demo, we describe a system that analyses medical videos from the gastrointestinal tract. Our system dissects the Tensorflow-based neural network to provide insights into the analysis and uses the resulting classification and rationale behind the classification to automatically generate an examination report for the patient's medical journal. Steven Alexander Hicks, Konstantin Pogorelov, Thomas de Lange, Mathias Lux, Mattis Jeppsson, Kristin Ranheim Randel, Sigrun Losada Eskeland, Pål Halvorsen, Michael Riegler 0001 |
MMSys | 9 |
| 2018 | HINDSIGHT: an R-based framework towards long short term memory (LSTM) optimizationabstractHyperparameter optimization is an important but often ignored part of successfully training Neural Networks (NN) since it is time consuming and rather complex. In this paper, we present HINDSIGHT, an open-source framework for designing and implementing NN that supports hyperparameter optimization. HINDSIGHT is built entirely in R and the current version focuses on Long Short Term Memory (LSTM) networks, a special kind of Recurrent Neural Networks (RNN). HINDSIGHT is designed in a way that it can easily be expanded to other types of Deep Learning (DL) algorithms such as Convolutional Neural Networks (CNN) or feed-forward Deep Neural Networks (DNN). The main goal of HINDSIGHT is to provide a simple and quick interface to get started with LSTM networks and hyperparameter optimization. Konstantinos Kousias, Michael Riegler 0001, Özgü Alay, Antonios Argyriou |
MMSys | 2 |
| 2018 | Opensea: open search based classification toolabstractThis paper presents an open-source classification tool for image and video frame classification. The classification takes a search-based approach and relies on global and local image features. It has been shown to work with images as well as videos, and is able to perform the classification of video frames in real-time so that the output can be used while the video is recorded, playing, or streamed. OpenSea has been proven to perform comparable to state-of-the-art methods such as deep learning, at the same time performing much faster in terms of processing speed, and can be therefore seen as an easy to get and hard to beat baseline. We present a detailed description of the software, its installation and use. As a use case, we demonstrate the classification of polyps in colonoscopy videos based on a publicly available dataset. We conduct leave-one-out-cross-validation to show the potential of the software in terms of classification time and accuracy. Konstantin Pogorelov, Zeno Albisser, Olga Ostroukhova, Mathias Lux, Dag Johansen, Pål Halvorsen, Michael Riegler 0001 |
MMSys | 7 |
| 2018 | Top-down saliency detection driven by visual classification
Francesca Murabito, Concetto Spampinato, Simone Palazzo, Daniela Giordano, Konstantin Pogorelov, Michael Riegler 0001 |
Comput. Vis. Image Underst. | 6 |
| 2018 | Mental health monitoring with multimodal sensing and machine learning: A surveyabstractPersonal and ubiquitous sensing technologies such as smartphones have allowed the continuous collection of data in an unobtrusive manner. Machine learning methods have been applied to continuous sensor data to predict user contextual information such as location, mood, physical activity, etc. Recently, there has been a growing interest in leveraging ubiquitous sensing technologies for mental health care applications, thus, allowing the automatic continuous monitoring of different mental conditions such as depression, anxiety, stress, and so on. This paper surveys recent research works in mental health monitoring systems (MHMS) using sensor data and machine learning. We focused on research works about mental disorders/conditions such as: depression, anxiety, bipolar disorder, stress, etc. We propose a classification taxonomy to guide the review of related works and present the overall phases of MHMS. Moreover, research challenges in the field and future opportunities are also discussed. Enrique Garcia-Ceja, Michael Riegler 0001, Tine Nordgreen, Petter Jakobsen, Ketil J. Oedegaard, Jim Tørresen |
Pervasive Mob. Comput. | 2 |
| 2017 | Smart Lifelogging: Recognizing Human Activities using PHASORabstractLifelog, Human Activity Recognition, Smartphones, Embedded Sensors, Smart-City, Heterogeneous Sensory Data Analytics.\nThis paper introduces a new idea for sensor data analytics, named PHASOR, that can recognize and stream individual human activities online. The proposed sensor concept can be utilized to solve some emerging problems in smartcity domain such as health care, urban mobility, or security by creating a lifelog of human activities. PHASOR is created from three ‘components’: ID, model, and Sensor. The first component is to identify which sensor is used to monitor which object (e.g., group of users, individual users, type of smart- phone). The second component decides suitable classifiers for human activities recognition. The last one includes two types: (1) physical sensors that utilize embedded sensors in smartphones to recognize human activities, (2) human factors that uses human interaction to personally increase the accuracy of the detection. The advantage of PHASOR is the error signal is inversely proportional to its lifetime, which is well-suited for lifelogging applications. The proposed concept is evaluated and compared to de-facto datasets as well as state-of-the-art of Human Activity Recognition (HAR) using smartphones, confirming that applying PHASOR can improves the accuracy of HAR. Minh-Son Dao, Duc-Tien Dang-Nguyen, Michael Riegler 0001, Cathal Gurrin |
ICPRAM | 3 |
| 2017 | The JORD System: Linking Sky and Social Multimedia Data to Natural DisastersabstractBeing able to automatically link social media information and data to remote-sensed data holds large possibilities for society and research. In this paper, we present a system called JORD that is able to autonomously collect social media data about technological and environmental disasters, and link it automatically to remote-sensed data. In addition, we demonstrate that queries in local languages that are relevant to the exact position of natural disasters retrieve more accurate information about a disaster event. To show the capabilities of the system, we present some examples of disaster events detected by the system. To evaluate the quality of the provided information and usefulness of JORD from the potential users point of view we include a crowdsourced user study. Kashif Ahmad, Michael Riegler 0001, Ans Riaz, Nicola Conci, Duc-Tien Dang-Nguyen, Pål Halvorsen |
ICMR | 2 |
| 2017 | LireSolr: A Visual Information Retrieval ServerabstractIn this paper, we present LireSolr, an open source image retrieval server, build on top of the LIRE library and the Apache Solr search server. With LireSolr, visual information retrieval can be run on a server, which allows better distribution of workloads and simplifies applications in several areas including mobile and web. Furthermore, we showcase several example scenarios how LireSolr can be used to point out the broad range of possibilities and applications. The system is easy to install and setup, and the large number of retrieval tools either provided by LIRE or by other Apache Solr is made easily available on the search server. Moreover, our tool demonstrates how predictions from CNNs can easily be used to extend the visual information retrieval functionality. Mathias Lux, Michael Riegler 0001, Pål Halvorsen, Glenn Macstravic |
ICMR | 2 |
| 2017 | ClusterTag: Interactive Visualization, Clustering and Tagging Tool for Big Image CollectionsabstractExploring and annotating collections of images without meta-data is a complex task which requires convenient ways of presenting datasets to a user. Visual analytics and information visualization can help users by providing interfaces, and in this paper, we present an open source application that allows users from any domain to use feature-based clustering of large image collections to perform explorative browsing and annotation. For this, we use various image feature extraction mechanisms, different unsupervised clustering algorithms and hierarchical image collection visualization. The performance of the presented open source software allows users to process and display thousands of images at the same time by utilizing heterogeneous resources such as GPUs and different optimization techniques. Konstantin Pogorelov, Michael Riegler 0001, Pål Halvorsen, Carsten Griwodz |
ICMR | 2 |
| 2017 | Multimodal Analysis of Image Search Intent: Intent Recognition in Image Search from User Behavior and Visual ContentabstractUsers search for multimedia content with different underlying motivations or intentions. Study of user search intentions is an emerging topic in information retrieval since understanding why a user is searching for a content is crucial for satisfying the user's need. In this paper, we aimed at automatically recognizing a user's intent for image search in the early stage of a search session. We designed seven different search scenarios under the intent conditions of finding items, re-finding items and entertainment. We collected facial expressions, physiological responses, eye gaze and implicit user interactions from 51 participants who performed seven different search tasks on a custom-built image retrieval platform. We analyzed the users' spontaneous and explicit reactions under different intent conditions. Finally, we trained machine learning models to predict users' search intentions from the visual content of the visited images, the user interactions and the spontaneous responses. After fusing the visual and user interaction features, our system achieved the F-1 score of 0.722 for classifying three classes in a user-independent cross-validation. We found that eye gaze and implicit user interactions, including mouse movements and keystrokes are the most informative features. Given that the most promising results are obtained by modalities that can be captured unobtrusively and online, the results demonstrate the feasibility of deploying such methods for improving multimedia retrieval platforms. Mohammad Soleymani 0001, Michael Riegler 0001, Pål Halvorsen |
ICMR | 2 |
| 2017 | Medical Multimedia Information Systems (MMIS)abstractIn hospitals all around the world, medical multimedia information systems have gained high importance over the last few years. One of the reasons is that an increasing number of interventions are performed in a minimally invasive way. These endoscopic inspections and surgeries are performed with a tiny camera -- the endoscope -- which produces a video signal that is used to control the intervention. Apart from the viewing purpose, the video signal is also used for automatic content analysis during the intervention as well as for post-surgical usage, such as communicating operation techniques, planning future interventions, and medical forensics. Another reason is video documentation, which is even enforced by law in some countries. The problem, however, is the sheer amount of unstructured medical videos that are added to the multimedia archive on a daily basis. Without proper management and a multimedia information system, the medical videos cannot be used efficiently for post-surgical scenarios. It is therefore already foreseeable that medical multimedia information systems will gain even more attraction in the next few years. In this tutorial we will introduce the audience to this challenging new field, describe the domain-specific characteristics and challenges of medical multimedia data, introduce related use cases, and talk about existing works -- contributed by the medical imaging and robotics community, but also already partly from the multimedia community -- as well as the many open issues and challenges that bear high research potential. Klaus Schöffmann, Bernd Münzer, Michael Riegler 0001, Pål Halvorsen |
ACM Multimedia | 3 |
| 2017 | A Holistic Multimedia System for Gastrointestinal Tract Disease DetectionabstractAnalysis of medical videos for detection of abnormalities and diseases requires both high precision and recall, but also real-time processing for live feedback and scalability for massive screening of entire populations. Existing work on this field does not provide the necessary combination of retrieval accuracy and performance.; [email protected] this paper, a multimedia system is presented where the aim is to tackle automatic analysis of videos from the human gastrointestinal (GI) tract. The system includes the whole pipeline from data collection, processing and analysis, to visualization. The system combines filters using machine learning, image recognition and extraction of global and local image features. Furthermore, it is built in a modular way so that it can easily be extended. At the same time, it is developed for efficient processing in order to provide real-time feedback to the doctors. Our experimental evaluation proves that our system has detection and localisation accuracy at least as good as existing systems for polyp detection, it is capable of detecting a wider range of diseases, it can analyze video in real-time, and it has a low resource consumption for scalability. Konstantin Pogorelov, Sigrun Losada Eskeland, Thomas de Lange, Carsten Griwodz, Kristin Ranheim Randel, Håkon Kvale Stensland, Duc-Tien Dang-Nguyen, Concetto Spampinato, Dag Johansen, Michael Riegler 0001, Pål Halvorsen |
MMSys | 10 |
| 2017 | KVASIR: A Multi-Class Image Dataset for Computer Aided Gastrointestinal Disease DetectionabstractAutomatic detection of diseases by use of computers is an important, but still unexplored field of research. Such innovations may improve medical practice and refine health care systems all over the world. However, datasets containing medical images are hardly available, making reproducibility and comparison of approaches almost impossible. In this paper, we present KVASIR, a dataset containing images from inside the gastrointestinal (GI) tract. The collection of images are classified into three important anatomical landmarks and three clinically significant findings. In addition, it contains two categories of images related to endoscopic polyp removal. Sorting and annotation of the dataset is performed by medical doctors (experienced endoscopists). In this respect, KVASIR is important for research on both single- and multi-disease computer aided detection. By providing it, we invite and enable multimedia researcher into the medical domain of detection and retrieval. Konstantin Pogorelov, Kristin Ranheim Randel, Carsten Griwodz, Sigrun Losada Eskeland, Thomas de Lange, Dag Johansen, Concetto Spampinato, Duc-Tien Dang-Nguyen, Mathias Lux, Peter Thelin Schmidt, Michael Riegler 0001, Pål Halvorsen |
MMSys | 11 |
| 2017 | Nerthus: A Bowel Preparation Quality Video DatasetabstractBowel preparation (cleansing) is considered to be a key precondition for successful colonoscopy (endoscopic examination of the bowel). The degree of bowel cleansing directly affects the possibility to detect diseases and may influence decisions on screening and follow-up examination intervals. An accurate assessment of bowel preparation quality is therefore important. Despite the use of reliable and validated bowel preparation scales, the grading may vary from one doctor to another. An objective and automated assessment of bowel cleansing would contribute to reduce such inequalities and optimize use of medical resources. This would also be a valuable feature for automatic endoscopy reporting in the future. In this paper, we present Nerthus, a dataset containing videos from inside the gastrointestinal (GI) tract, showing different degrees of bowel cleansing. By providing this dataset, we invite multimedia researchers to contribute in the medical field by making systems automatically evaluate the quality of bowel cleansing for colonoscopy. Such innovations would probably contribute to improve the medical field of GI endoscopy. Konstantin Pogorelov, Kristin Ranheim Randel, Thomas de Lange, Sigrun Losada Eskeland, Carsten Griwodz, Dag Johansen, Concetto Spampinato, Mario Taschwer, Mathias Lux, Peter Thelin Schmidt, Michael Riegler 0001, Pål Halvorsen |
MMSys | 11 |
| 2017 | The same, only different: Contrasting mobile operator behavior from crowdsourced datasetabstractCrowdsourcing mobile network performance evaluation is rapidly gaining popularity, with new applications aiming to deliver more accurate and reliable results every day. From the perspective of end-users, these utilities help them estimate the performance of their service provider in terms of throughput, latency and other key performance indicators of the network. In this paper, we build ORCA: Operator Classifier, a Machine Learning (ML) based framework to define and determine the behavior of Mobile Network Operators (MNOs) from crowdsourced datasets. We investigate whether one can differentiate MNOs by using crowdsourced end-to-end network measurements. We consider different performance metrics (e.g. Download (DL)/Upload (UL) data rate, latency, signal strength) and study the impact of them individually but also collectively on differentiating MNOs. We use RTR Open Data, an open dataset of broadband measurements provided by the Austrian Regulatory Authority for Broadcasting and Telecommunications (RTR), to characterize the three major mobile native operators and two virtual operators in Austria. Our results show that ORCA can be used to identify patterns between various mobile systems and disclose their differences from the end-user perspective. Konstantinos Kousias, Cise Midoglu, Özgü Alay, Andra Lutu, Antonios Argyriou, Michael Riegler 0001 |
PIMRC | 6 |
| 2017 | Efficient disease detection in gastrointestinal videos - global features versus neural networksabstractAnalysis of medical videos from the human gastrointestinal (GI) tract for detection and localization of abnormalities like lesions and diseases requires both high precision and recall. Additionally, it is important to support efficient, real-time processing for live feedback during (i) standard colonoscopies and (ii) scalability for massive population-based screening, which we conjecture can be done using a wireless video capsule endoscope (camera-pill). Existing related work in this field does neither provide the necessary combination of accuracy and performance for detecting multiple classes of abnormalities simultaneously nor for particular disease localization tasks. In this paper, a complete end-to-end multimedia system is presented where the aim is to tackle automatic analysis of GI tract videos. The system includes an entire pipeline ranging from data collection, processing and analysis, to visualization. The system combines deep learning neural networks, information retrieval, and analysis of global and local image features in order to implement multi-class classification, detection and localization. Furthermore, it is built in a modular way, so that it can be easily extended to deal with other types of abnormalities. Simultaneously, the system is developed for efficient processing in order to provide real-time feedback to the doctors and for scalability reasons when potentially applied for massive population-based algorithmic screenings in the future. Initial experiments show that our system has multi-class detection accuracy and polyp localization precision at least as good as state-of-the-art systems, and provides additional novelty in terms of real-time performance, low resource consumption and ability to extend with support for new classes of diseases. Konstantin Pogorelov, Michael Riegler 0001, Sigrun Losada Eskeland, Thomas de Lange, Dag Johansen, Carsten Griwodz, Peter Thelin Schmidt, Pål Halvorsen |
Multim. Tools Appl. | 2 |
| 2017 | From Annotation to Computer-Aided Diagnosis: Detailed Evaluation of a Medical Multimedia SystemabstractHolistic medical multimedia systems covering end-to-end functionality from data collection to aided diagnosis are highly needed, but rare. In many hospitals, the potential value of multimedia data collected through routine examinations is not recognized. Moreover, the availability of the data is limited, as the health care personnel may not have direct access to stored data. However, medical specialists interact with multimedia content daily through their everyday work and have an increasing interest in finding ways to use it to facilitate their work processes. In this article, we present a novel, holistic multimedia system aiming to tackle automatic analysis of video from gastrointestinal (GI) endoscopy. The proposed system comprises the whole pipeline, including data collection, processing, analysis, and visualization. It combines filters using machine learning, image recognition, and extraction of global and local image features. The novelty is primarily in this holistic approach and its real-time performance, where we automate a complete algorithmic GI screening process. We built the system in a modular way to make it easily extendable to analyze various abnormalities, and we made it efficient in order to run in real time. The conducted experimental evaluation proves that the detection and localization accuracy are comparable or even better than existing systems, but it is by far leading in terms of real-time performance and efficient resource consumption. Michael Riegler 0001, Konstantin Pogorelov, Sigrun Losada Eskeland, Peter Thelin Schmidt, Zeno Albisser, Dag Johansen, Carsten Griwodz, Pål Halvorsen, Thomas de Lange |
ACM Trans. Multim. Comput. Commun. Appl. | 1 |
| 2016 | GPU-Accelerated Real-Time Gastrointestinal Diseases DetectionabstractThe process of finding diseases and abnormalities during live medical examinations has for a long time depended mostly on the medical personnel, with a limited amount of computer support. However, computer-based medical systems are currently emerging in domains like endoscopies of the gastrointestinal (GI) tract. In this context, we aim for a system that enables automatic analysis of endoscopy videos, where one use case is live computer-assisted endoscopy that increases disease-and abnormality-detection rates. In this paper, a system that tackles live automatic analysis of endoscopy videos is presented with a particular focus on the system's ability to perform in real time. The presented system utilizes different parts of a heterogeneous architecture and can be used for automatic analysis of high-definition colonoscopy videos (and a fully automated analysis of video from capsular endoscopy devices). We describe our implementation and report the system performance of our GPU-based processing framework. The experimental results show real-time stream processing and low resource consumption, and a detection precision and recall level at least as good as existing related work. Konstantin Pogorelov, Michael Riegler 0001, Pål Halvorsen, Peter Thelin Schmidt, Carsten Griwodz, Dag Johansen, Sigrun Losada Eskeland, Thomas de Lange |
CBMS | 2 |
| 2016 | ChaLearn Joint Contest on Multimedia Challenges Beyond Visual Analysis: An overviewabstractThis paper provides an overview of the Joint Contest on Multimedia Challenges Beyond Visual Analysis. We organized an academic competition that focused on four problems that require effective processing of multimodal information in order to be solved. Two tracks were devoted to gesture spotting and recognition from RGB-D video, two fundamental problems for human computer interaction. Another track was devoted to a second round of the first impressions challenge of which the goal was to develop methods to recognize personality traits from short video clips. For this second round we adopted a novel collaborative-competitive (i.e., coopetition) setting. The fourth track was dedicated to the problem of video recommendation for improving user experience. The challenge was open for about 45 days, and received outstanding participation: almost 200 participants registered to the contest, and 20 teams sent predictions in the final stage. The main goals of the challenge were fulfilled: the state of the art was advanced considerably in the four tracks, with novel solutions to the proposed problems (mostly relying on deep learning). However, further research is still required. The data of the four tracks will be available to allow researchers to keep making progress in the four tracks. Hugo Jair Escalante, Víctor Ponce-López, Jun Wan 0001, Michael Riegler 0001, Albert Clapés, Sergio Escalera, Isabelle Guyon, Xavier Baró, Pål Halvorsen, Henning Müller, Martha A. Larson |
ICPR | 4 |
| 2016 | Multimedia and Medicine: Teammates for Better Disease Detection and SurvivalabstractHealth care has a long history of adopting technology to save lives and improve the quality of living. Visual information is frequently applied for disease detection and assessment, and the established fields of computer vision and medical imaging provide essential tools. It is, however, a misconception that disease detection and assessment are provided exclusively by these fields and that they provide the solution for all challenges. Integration and analysis of data from several sources, real-time processing, and the assessment of usefulness for end-users are core competences of the multimedia community and are required for the successful improvement of health care systems. We have conducted initial investigations into two use cases surrounding diseases of the gastrointestinal (GI) tract, where the detection of abnormalities provides the largest chance of successful treatment if the initial observation of disease indicators occurs before the patient notices any symptoms. Although such detection is typically provided visually by applying an endoscope, we are facing a multitude of new multimedia challenges that differ between use cases. In real-time assistance for colonoscopy, we combine sensor information about camera position and direction to aid in detecting, investigate means for providing support to doctors in unobtrusive ways, and assist in reporting. In the area of large-scale capsular endoscopy, we investigate questions of scalability, performance and energy efficiency for the recording phase, and combine video summarization and retrieval questions for analysis. Michael Riegler 0001, Mathias Lux, Carsten Griwodz, Concetto Spampinato, Thomas de Lange, Sigrun Losada Eskeland, Konstantin Pogorelov, Wallapak Tavanapong, Peter Thelin Schmidt, Cathal Gurrin, Dag Johansen, Håvard D. Johansen, Pål Halvorsen |
ACM Multimedia | 1 |
| 2016 | OpenVQ: A Video Quality Assessment ToolkitabstractThis paper presents an open source video quality assessment tool called OpenVQ and OPVQ, an objective quality metric based on work of the Video Quality Experts Group. It was primarily developed to satisfy the need of the community for a freely accessible and easy-to-use quality assessment tool, which would remove the need for using throughly outdated methods that is still prevalent because only those are easily available. OpenVQ is implemented as a toolbox of full-reference quality assessment methods, which can be extended with improved methods in the future. The primary method provided by OpenVQ at this time is OPVQ, the Open Perceptual Video Quality metric. It is very much inspired by the formal model of ITU-T Rec. J.247 Annex B, however with many modifications to deal with errors and inconsistencies in formulas and pseudo code, and restrictions to avoid violating known patents. OPVQ has been validated with several IRRCyN datasets and was found to yield results similar to those reported in ITU.T J.247. OpenVQ implements also PSNR (Peak signal-to-noise-ratio), because it is in high demand in spite of its bad performance, and SSIM (Structural similarity index), an image quality metric that is known to perform quite well in many cases. Kristian Skarseth, Henrik Bjørlo, Pål Halvorsen, Michael Riegler 0001, Carsten Griwodz |
ACM Multimedia | 4 |
| 2016 | LIRE: open source visual information retrievalabstractWith an annual growth rate of 16.2% of taken photos a year, researchers predict an almost unbelievable number of 4.9 trillion stored images in 2017. Nearly 80% of these photos in 2017 will be taken with mobile phones. To be able to cope with this immense amount of visual data in a fast and accurate way, a visual information retrieval systems are needed for various domains and applications. LIRE, short for Lucene Image Retrieval, is a light weight and easy to use Java library for visual information retrieval. It allows developers and researchers to integrate common content based image retrieval approaches in their applications and research projects. LIRE supports global and local image features and can cope with millions of images using approximate search and distributing indexes on the cloud. In this demo we present a novel tool called F-search that emphasize the core strengths of LIRE: lightness, speed and accuracy. Mathias Lux, Michael Riegler 0001, Pål Halvorsen, Konstantin Pogorelov, Nektarios Anagnostopoulos |
MMSys | 2 |
| 2016 | Efficient processing of videos in a multi-auditory environment using device lending of GPUsabstractIn this paper, we present a demo that utilizes Device Lending via PCI Express (PCIe) in the context of a multi-auditory environment. Device Lending is a transparent, low-latency cross-machine PCIe device sharing mechanism without any the need for implementing application-specific distribution mechanisms. As workload, we use a computer-aided diagnosis system that is used to automatically find polyps and mark them for medical doctors during a colonoscopy. We choose this scenario because one of the main requirements is to perform the analysis in real-time. The demonstration consists of a setup of two computers that demonstrates how Device Lending can be used to improve performance, as well as its effect of providing the performance needed for real-time feedback. We also present a performance evaluation that shows its real-time capabilities of it. Konstantin Pogorelov, Michael Riegler 0001, Jonas Markussen, Håkon Kvale Stensland, Pål Halvorsen, Carsten Griwodz, Sigrun Losada Eskeland, Thomas de Lange |
MMSys | 2 |
| 2016 | Heimdallr: a dataset for sport analysisabstractIn this paper, we present Heimdallr, a dataset that aims to serve two different purposes. The first purpose is action recognition and pose estimation, which requires a dataset of annotated sequences of athlete skeletons. We employed a crowdsourcing platform where people around the world were asked to annotate frames and obtained more than 3000 fully annotated frames for 42 different sequences with a variety of poses and actions. The second purpose is an improved understanding of crowdworkers, and for this purpose, we collected over 10000 written feedbacks from 592 crowdworkers. This is valuable information for crowdsourcing researchers who explore algorithms for worker quality assessment. In addition to the complete dataset, we also provide the code for the application that has been used to collect the data as an open source software. Michael Riegler 0001, Duc-Tien Dang-Nguyen, Bård Winther, Carsten Griwodz, Konstantin Pogorelov, Pål Halvorsen |
MMSys | 1 |
| 2016 | Right inflight?: a dataset for exploring the automatic prediction of movies suitable for a watching situationabstractIn this paper, we present the dataset Right Inflight developed to support the exploration of the match between video content and the situation in which that content is watched. Specifically, we look at videos that are suitable to be watched on an airplane, where the main assumption is that that viewers watch movies with the intent of relaxing themselves and letting time pass quickly, despite the inconvenience and discomfort of flight. The aim of the dataset is to support the development of recommender systems, as well as computer vision and multimedia retrieval algorithms capable of automatically predicting which videos are suitable for inflight consumption. Our ultimate goal is to promote a deeper understanding of how people experience video content, and of how technology can support people in finding or selecting video content that supports them in regulating their internal states in certain situations. Right Inflight consists of 318 human-annotated movies, for which we provide links to trailers, a set of pre-computed low-level visual, audio and text features as well as user ratings. The annotation was performed by crowdsourcing workers, who were asked to judge the appropriateness of movies for inflight consumption. Michael Riegler 0001, Martha A. Larson, Concetto Spampinato, Pål Halvorsen, Mathias Lux, Jonas Markussen, Konstantin Pogorelov, Carsten Griwodz, Håkon Kvale Stensland |
MMSys | 1 |
| 2016 | Computer aided disease detection system for gastrointestinal examinationsabstractIn this paper, we present the computer-aided diagnosis part of the EIR system [9], which can support medical experts in the task of detecting diseases and anatomical landmarks in the gastrointestinal (GI) system. This includes automatic detection of important findings in colonoscopy videos and marking them for the doctors. EIR is designed in a modular way so that it can easily be extended for other diseases. For this demonstration, we will focus on polyp detection, as our system is trained with the ASU-Mayo Clinic polyp database [5]. Michael Riegler 0001, Konstantin Pogorelov, Jonas Markussen, Mathias Lux, Håkon Kvale Stensland, Thomas de Lange, Carsten Griwodz, Pål Halvorsen, Dag Johansen, Peter Thelin Schmidt, Sigrun Losada Eskeland |
MMSys | 1 |
| 2016 | Device lending in PCI express networksabstractThe challenge of scaling IO performance of multimedia systems to demands of their users has attracted much research. A lot of effort has gone into development of distributed systems that add little latency and computing overhead. For machines in PCI Express (PCIe) clusters, we propose Device Lending as a novel solution which works at a system level. Lars Bjørlykke Kristiansen, Jonas Markussen, Håkon Kvale Stensland, Michael Riegler 0001, Hugo Kohmann, Friedrich Seifert, Roy Nordstrøm, Carsten Griwodz, Pål Halvorsen |
NOSSDAV | 4 |
| 2016 | Tiling in Interactive Panoramic Video: Approaches and EvaluationabstractInteractive panoramic systems are currently on the rise. However, one of the major challenges in such a system is the overhead involved in transferring a full-quality panorama to the client when only a part of the panorama is used to extract a virtual view. Thus, such a system should maximize the user experience while simultaneously minimizing the bandwidth required. In this paper, we apply tiling to deliver different quality levels for different parts of the panorama. Tiling has traditionally been applied to the delivery of very high-resolution content to clients. Here, we apply similar ideas in a real-time interactive panoramic video system. A major challenge lies in the movement of such a virtual view, for which clients' regions of interest change dynamically and independently from each other. We show that our algorithms, which progressively increase in quality toward the point of the view, manage to (i) reduce the bandwidth requirement and (ii) provide a similar quality of experience (QoE) compared to a full panorama system. Vamsidhar Reddy, Michael Riegler 0001, Ragnhild Eg, Carsten Griwodz, Pål Halvorsen |
IEEE Trans. Multim. | 2 |
| 2015 | Expert driven semi-supervised elucidation tool for medical endoscopic videosabstractIn this paper, we present a novel application for elucidating all kind of videos that require expert knowledge, e.g., sport videos, medical videos etc., focusing on endoscopic surgery and video capsule endoscopy. In the medical domain, the knowledge of experts for tagging and interpretation of videos is of high value. As a result of the stressful working environment of medical doctors, they often simply do not have time for extensive annotations. We therefore present a semi-supervised method to gather the annotations in a very easy and time saving way for the experts and we show how this information can be used later on. Zeno Albisser, Michael Riegler 0001, Pål Halvorsen, Carsten Griwodz, Ilangko Balasingham, Cathal Gurrin |
MMSys | 2 |
| 2015 | Exploitation of producer intent in relation to bandwidth and QoE for online video streaming servicesabstractThis paper is the product of recent advances in research on users' intent during multimedia content retrieval. Our goal is to save bandwidth while streaming video clips from a browsable on-demand service, while maintaining or even improving the users' quality of experience (QoE). Understanding user intent allows us to predict whether streaming a particular video in a low quality constitutes a reduced QoE for a user. However, many VoD streaming services today are used by users for a wide variety of reasons, meaning that user intent cannot be inferred from their use of the service alone. However, our investigation demonstrates that user intent does in most cases coincide with producer intent. We can also demonstrate that the latter can be inferred from the content itself as well as associated metadata. By transitivity, we can choose a default video quality that satisfies the users QoE in the majority of cases. Michael Riegler 0001, Lilian Calvet, Amandine Calvet, Pål Halvorsen, Carsten Griwodz |
NOSSDAV | 1 |
| 2014 | VideoJot: A Multifunctional Video Annotation ToolabstractVideos are becoming more and more a tool of communication. There are how-to videos, people are discussing actions of others based on their recorded performance, e.g., in soccer, or they simply record videos of great moments and show them to friends and family. In this paper we focus on very specific how-to videos and present a novel, web based annotation tool, that combines (i) zoom, (ii) drawing, and (iii) temporal social bookmarking in video streams. Moreover, we present a short study on the usefulness of the tool to communicate general concepts of a specific video game based on a captured game session. Michael Riegler 0001, Mathias Lux, Vincent Charvillat, Axel Carlier, Raynor Vliegendhart, Martha A. Larson |
ICMR | 1 |
| 2014 | How 'How' Reflects What's What: Content-based Exploitation of How Users Frame Social ImagesabstractIn this paper, we introduce the concept of intentional framing, defined as the sum of the choices that a photographer makes on how to portray the subject matter of an image. We carry out analysis experiments that demonstrate the existence of a correspondence between image similarity that is calculated automatically on the basis of global feature representations, and image similarity that is perceived by humans at the level of intentional frames. Intentional framing has profound implications: The existence of a fundamental image-interpretation principle that explains the importance of global representations in capturing human-perceived image semantics reaches beyond currently dominant assumptions in multimedia research. The ability of fast global-feature approaches to compete with more `sophisticated' approaches, which are computationally more complex, is demonstrated using a simple search method (SimSea) to classify a large (2M) collection of social images by tag class. In short, intentional framing provides a principled connection between human interpretations of images and lightweight, fast image processing methods. Moving forward, it is critical that the community explicitly exploits such approaches, as the social image collections that we tackle, continue to grow larger. Michael Riegler 0001, Martha A. Larson, Mathias Lux, Christoph Kofler |
ACM Multimedia | 1 |
| 2014 | Gone: an interactive experience for two peopleabstractIn this paper we present a multimedia art installation which uses human computer interaction to give the user the possibility to experience how blind people perceive the world and how hard it can be. The installation follows the classical co-operative game pattern, where a group of people - in this case two - have to work together to achieve a goal. With these basic characteristics in mind we consider our submission a serious game. With this serious game we show how multimedia can be used for making people more attentive for problems of other people and that multimedia, and in this case serious games, are indeed a useful tool for letting people experience situations they have not been aware of before. Michael Riegler 0001, Mathias Lux, Christian Zellot, Lukas Knoch, Horst Schnattler, Sabrina Napetschnig, Julian Kogler, Claus Degendorfer, Norbert Spot, Manuel Zoderer |
ACM Multimedia | 1 |
| 2014 | Fashion 10000: an enriched social image dataset for fashion and clothingabstractIn this work, we present a new social image dataset related to the fashion and clothing domain. The dataset contains more than 32000 images, their context and social metadata. Furthermore the dataset is enriched with several types of annotations collected from the Amazon Mechanical Turk (AMT) crowdsourcing platform, which can serve as ground truth for various content analysis algorithms. This dataset has been successfully used at the Crowdsourcing task of the 2013 MediaEval Multimedia Benchmarking initiative. The dataset contributes to several research areas such as Crowdsourcing, multimedia content and context analysis as well as hybrid human/automatic approaches. In this paper, the dataset is described in detail and the dataset collection strategy, statistics, applications of dataset and its contribution to MediaEval 2013 is discussed. Babak Loni, Lei Yen Cheung, Michael Riegler 0001, Alessandro Bozzon, Luke R. Gottlieb, Martha A. Larson |
MMSys | 3 |
| 2013 | Annotation of endoscopic videos on mobile devices: a bottom-up approachabstractVideo annotation is a tedious task. But especially in medical domain the knowledge of experts for the interpretation of videos is of high value. Typically medical doctors do not have time for extensive annotation, but are used to manual notes, speech recordings, and pointing. In this demo paper we present an application for annotation of medical videos, focusing on endoscopic surgery. We adopt common interaction method of medical experts to mobile computing and provide a tool for experts to annotate videos by drawing on the video and recording speech annotations. Mathias Lux, Michael Riegler 0001 |
MMSys | 2 |