António Cunha

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22ranked-venue papers
0as first author
17since 2021 · last 2023
0000-0002-3458-7693ORCID · verified

Domains — the database's venue-derived domains; a paper can count in several

Applied, interdisciplinary, general and emerging computing · 18 · 15 since 2021Artificial intelligence and machine learning · 4 · 2 since 2021Graphics, computer vision, multimedia, augmented reality and games · 1Human-computer interaction and ubiquitous computing · 1
YearPublicationVenuePosition
2023 Evaluating Data Augmentation for Grapevine Varieties Identification
abstract
The grapevine variety identification is important in the wine’s production chain since it is related to its quality, authenticity and singularity. In this study, we addressed the data augmentation approach to identify grape varieties with images acquired in-field. We tested the static transformations, RandAugment, and Cutmix methods. Our results showed that the best result was achieved by the Static method generating 5 images per sample (F1 = 0.89), however without a significative difference if compared with RandAugment generating 2 images. The worst performance was achieved by CutMix (F1 = 0.86).
Gabriel A. Carneiro, Alexandre Neto, Ana Cláudia Teixeira, António Cunha, Joaquim João Sousa
IGARSS4
2023 Transfer-Learning On Land Use And Land Cover Classification
abstract
In this study, we evaluated the use of small pre-trained 3D Convolutional Neural Networks (CNN) on land use and land cover (LULC) slide-window-based classification. We pretrained the small models in a dataset with origin in the Eurosat dataset and evaluated the benefits of the transfer-learning plus fine-tuning for four different regions using Sentinel-2 L1C imagery (bands of 10 and 20m of spatial resolution), comparing the results to pre-trained models and trained from scratch. The models achieved an F1 Score of between 0.69-0.80 without significative change when pre-training the model. However, for small datasets, pre-training the model improved the classification by up to 3%.
Gabriel A. Carneiro, Ana Cláudia Teixeira, António Cunha, Joaquim João Sousa
IGARSS3
2023 Automatic Identification of Public Lighting Failures in Satellite Images: A Case Study in Seville, Spain
abstract
Public lighting is crucial for maintaining the safety and well-being of communities. Current inspection methods involve examining the luminaires during the day, but this approach has drawbacks, including energy consumption, delay in detecting issues, and high costs and time investment. Utilising deep learning based automatic detection is an advanced method that can be used for identifying and locating issues in this field. This study aims to use deep learning to automatically detect burnt-out street lights, using Seville (Spain) as a case study. The study uses high-resolution night time imagery from the JL1-3B satellite to create a dataset called NLight, which is then divided into three subsets: NL1, NL2, and NT. The NL1 and NL2 datasets are used to train and evaluate YOLOv5 and YOLOv7 segmentation models for instance segmentation of streets. And then, distance outliers were detected to find the lights off. Finally, the NT dataset is used to evaluate the effectiveness of the proposed methodology. The study finds that YOLOv5 achieved a mask mAP of 57.7%, and the proposed methodology had a precision of 30.8% and a recall of 28.3%. The main goal of this work is accomplished, but there is still space for future work to improve the methodology.
Ana Cláudia Teixeira, Leonor Batista, Gabriel A. Carneiro, António Cunha, Joaquim João Sousa
IGARSS4
2023 Street Light Segmentation in Satellite Images Using Deep Learning
abstract
Public lighting plays a very important role for society's safety and quality of life. The identification of faults in public lighting is essential for the maintenance and prevention of safety. Traditionally, this task depends on human action, through checking during the day, representing expenditure and waste of energy. Automatic detection with deep learning is an innovative solution that can be explored for locating and identifying of this kind of problem. In this study, we present a first approach, composed of several steps, intending to obtain the segmentation of public lighting, using Seville (Spain) as case study. A dataset called NLight was created from a nighttime image taken by the JL1-3B satellite, and four U-Net and FPN architectures were trained with different backbones to segment part of the NLight. The U-Net with InceptionResNetv2 proved to be the model with the best performance, obtained 761 of 815, correct locations (93.4%). This model was used to predict the segmentation of the remaining dataset. This study provides the location of lamps so that we can identify patterns and possible lighting failures in the future.
Ana Cláudia Teixeira, Gabriel A. Carneiro, Vítor Filipe, António Cunha, Joaquim João Sousa
IGARSS4
2023 Evaluating YOLO Models for Grape Moth Detection in Insect Traps
abstract
The grape moth is a common pest that affects grapevines by consuming both fruit and foliage, rendering grapes deformed and unsellable. Integrated pest management for the grape moth heavily relies on pheromone traps, which serve a crucial function by identifying and tracking adult moth populations. This information is then used to determine the most appropriate time and method for implementing other control techniques. This study aims to find the best method for detecting small insects. We evaluate the following recent YOLO models: v5, v6, v7, and v8 for detecting and counting grape moths in insect traps. The best performance was achieved by YOLOv8, with an average precision of 92.4% and a counting error of 8.1%.
Ana Cláudia Teixeira, Gabriel A. Carneiro, Raul Morais, Joaquim João Sousa, António Cunha
IGARSS5
2023 Automatic Detection of Abandoned Vineyards Using Aerial Imagery
abstract
The European Union (EU) established through the Common Agricultural Policy (CAP) an aid system and subsidies for farmers that cultivate vineyards. Eligible areas should be controlled and registered in Geographic Information Systems. The agencies paying this support must check that the parcels have an agricultural activity through an on-the-spot check or the analysis of aerial or satellite images. Abandonment situations lead to the cancellation of aid payments. In the Douro Demarcated Region of Portugal, inspections are conducted according to EU-defined methods. However, due to the vast size of the region, which spans approximately 250,000 hectares with vineyard cultures occupying 43,843 hectares, the analysis time and specialized human resources required for these inspections are significant.In this study, we curated a new dataset for training convolutional neural networks (CNNs) and fine-tuned pretrained VGG models to classify vineyards as abandoned or non-abandoned. The baseline model achieved an accuracy of 95.1% on the test dataset, while the top-performing model achieved an impressive overall accuracy and F1-score of 99% for both classes.
Igor Teixeira, Joaquim João Sousa, António Cunha
IGARSS3
2023 Lung CT image synthesis using GANs
José Mendes, Tânia Pereira 0001, Francisco Silva 0002, Julieta Frade, Joana Morgado, Cláudia Freitas, Eduardo Negrão, Beatriz Flor De Lima, Miguel Correia Da Silva, António J. Madureira, José Luís Costa, Venceslau Hespanhol, António Cunha, Hélder P. Oliveira
Expert Syst. Appl.14
2022 PS-InSAR Target Classification Using Deep Learning
abstract
Multi-temporal InSAR (MT-InSAR) observations, which enable deformation monitoring at an unprecedented scale, are usually affected by decorrelation and other noise inducing factors. Such observations (PS - Persistent scatterers), are usually in the order of several thousand, making their respective evaluation frequently computationally expensive. In the present study, we propose an approach for the detection of MT-InSAR outlying observations through the implementation of Convolutional Neural Networks (CNN) classification models. For each PS, the corresponding MT-InSAR parameters and the respective parameters of the neighboring scatterers and its relative position are considered. Tests in two independent datasets, covering the regions of Bratislava city and the suburbs of Prievidza, Slovakia, were performed. The results showed that such models offer a robust and reduced computation time method for the evaluation of MT-InSAR outlying observations. However, the applicability of these models is limited by the deformation pattern in which such models were trained.
Pedro Aguiar, António Cunha, Matus Bakon, Antonio M. Ruiz-Armenteros, Joaquim João Sousa
IGARSS2
2022 Grapevine Varieties Identification Using Vision Transformers
abstract
The grape variety plays an important role in the wine production chain, thus identifying it is crucial for production control. Ampelographers, professionals who identify grape varieties through plant visual analysis, are scarce, and molecular markers are expansive to identify grape varieties on a large scale. In this context, Deep Learning models become an effective way to handle ampelographers scarcity. In this work, we explore the benefit of using deep learning vision transformers architecture relative to conventional CNN to identify 12 grapevine varieties using leaf-centred RGB images acquired in the field. We train an Xception model as a baseline and four different configurations of the ViT_B model. The best model achieved 0.96 of Fl-score, outperforming the state-of-the-art convolutional-based model in the used dataset.
Gabriel A. Carneiro, Luís Pádua, Emanuel Peres, Raul Morais, Joaquim João Sousa, António Cunha
IGARSS6
2022 Segmentation as a Preprocessing Tool for Automatic Grapevine Classification
abstract
The grapevine variety plays an important role in wine chain production, thus identifying it is crucial for control activities. However, the specialists responsible for identifying the different varieties, mainly through visual analysis, are disappearing. In this scenario, Deep Learning (DL) classification techniques become a possible solution to handle professionals' scarcity. Nevertheless, previous experiments show that trained classification models use the background information to make decisions, which should be avoided. In this paper, we present a study allowing the assessment of removing background regions from the grapevine images in the improvement classification using DL models. The Xception model is trained with a normal dataset and its segmented version. The Local Interpretable Model-Agnostic Explanations (LIME), Grad-CAM, and Grad-CAM++ approaches are used to visualize the segmentation impact in classification decisions. F1-score of 0.92 and 0.94 were achieved, respectively, for segmented-dataset and normal-dataset trained models. Despite the model trained with the segmented-dataset to achieve a worse performance, the Explainable Artificial Intelligence (XAI) approaches showed that it looks into more reliable regions when making decisions.
Gabriel A. Carneiro, Luís Pádua, Emanuel Peres, Raul Morais, Joaquim João Sousa, António Cunha
IGARSS6
2022 Deep Learning Approach for Terrace Vineyards Detection from Google Earth Satellite Imagery
abstract
On rugged slopes overlooking the Douro River we find the Alto Douro Wine Region in Portugal, populated by plantations in schist lands of difficult access and mostly manual work. The combined features of this region are a source of motivation to explore remote sensing techniques associated with artificial intelligence. In this paper, a preliminary approach for terrace vineyards detection is presented. This is a key-enabling task towards the achievement of important goals such as multi-temporal crop evaluation and cultures characterization. The proposed methodology consists in the application of a deep learning model (U-net) to detect the terrace vineyards using satellite images dataset acquired with Google Earth Pro. The proposed methodology showed very promising detection capabilities.
Nuno Figueiredo, Alexandre Neto, António Cunha, Joaquim João Sousa, António M. R. Sousa
IGARSS3
2022 Detecting Earthquakes in SAR Interferogram with Vision Transformer
abstract
SAR Interferometry (InSAR) techniques are for detecting and monitoring ground deformation all over the planet. Natural disasters such as volcanoes and earthquakes deformations are among the main applications, and the great developments that we have witnessed in recent years suggests that near real-time monitoring will soon be possible. InSAR is developing fast - space agencies are launching more satellites, leading to exponential data growth. Consequently, conventional techniques cannot process all the acquired data. Modern deep learning methods can be a solution since they reach high accuracy in automatically detecting patterns in images and are fast to operate. In this work, we explore the contribution of deep learning vision transformer models to automatically detect seismic deformation in SAR interferograms. A VGG19 model is trained as baseline and ViT model uses$256\times 256$pixels patches and the full interferogram. The ViT model outperforms the state-of-the-art both for patch and full interferogram approaches, achieving 0.88 and 0.92 F1-score, respectively.
Joaquim João Sousa, António Cunha
IGARSS3
2022 Using Deep Learning for Detection and Classification of Insects on Traps
abstract
Insect pests are the main cause of loss of productivity and quality in crops worldwide. Insect monitoring becomes necessary for the early detection of pests and thus avoiding the excessive use of pesticides. Automatic detection of insects attracted by traps is a form of monitoring. Modern data-driven methods present great results for object detection when representative datasets are available, but public datasets for insect detection are few and small. Pest24 public dataset is extensive, but noisy resulting in a poor detection rate. In this work, we aim to improve insect detection in the Pest24 dataset. We propose the creation of three sub-datasets selecting the highest represented classes, the highest colour discrepancy, and the one with the highest relative scale, respectively. Several Faster R-CNN and YOLOv5 architectures are explored, and the best results are achieved with the YOLOv5 with an mAP of 95.5%.
Ana Cláudia Teixeira, Alexandre Neto, Raul Morais, Joaquim João Sousa, António Cunha
IGARSS6
2021 Stacking Approach for Lung Cancer EGFR Mutation Status Prediction from CT Scans
abstract
Due to the huge mortality rate of lung cancer, there is a strong need for developing solutions that help with the early diagnosis and the definition of the most appropriate treatment. In the particular case of target therapy, effective genotyping of the tumor is fundamental since this treatment uses targeted drugs that can induce death in cancer cells. The biopsy is the traditional method to assess the genotype information but it is extremely invasive and painful. Medical imaging is a valuable alternative to biopsies, considering the potential to extract imaging features correlated with specific genomic alterations. Regarding the limitations of single model approaches for gene mutation status predictions, ensemble strategies might bring valuable benefits by combining the strengths and weaknesses of the aggregated methods. This preliminary work aims to provide further advances in the radiogenomics field by studying the use of ensemble methods to predict the Epidermal Growth Factor Receptor (EGFR) mutation status in lung cancer. The best result obtained for the proposed ensemble approach was an AUC of 0.706 (± 0.122). However, the ensemble did not outperform the single models with AUC values of 0.712 (± 0.119) for Logistic Regression, 0.711 (± 0.119) for Support Vector Machine and 0.712 (± 0.120) for Elastic Net. The high correlation found on the decisions of each single model might be a plausible explanation for this behavior, which caused the ensemble to misclassify the same examples as the single models.
Alexandra Ventura, Tânia Pereira 0001, Francisco Silva 0002, Cláudia Freitas, António Cunha, Hélder P. Oliveira
BIBM5
2021 Grapevine Variety Identification Through Grapevine Leaf Images Acquired in Natural Environment
abstract
In this paper we present a Deep Learning-based methodology to automatically classify 12 of the most representative grape-varieties existing in the Douro Demarked region, Portugal. The dataset used consisted of images of leaves at different stages of development, collected on their natural environment. The development of such methodologies becomes particularly important, in a scenario in which ampeleographers are disappearing, creating a gap in the task of inspection of grape varieties. Our approach was based on the transfer learning of the Xcepetion model, using Focal Loss, adaptive learning rate decay and SGD. The model obtained a F1 score of 0.93. To clearly understand the predictions of the model, and realize which regions of the image contributed the most to the classification, the LIME library was used. This way it was possible to identify the parts of the images that were considered for and against each prediction.
Gabriel S. Carneiro, Luís Pádua, Joaquim João Sousa, Emanuel Peres, Raul Morais, António Cunha
IGARSS6
2021 A multi-task CNN approach for lung nodule malignancy classification and characterization
Sónia Marques, Filippo Schiavo, Carlos Ferreira 0006, João Pedrosa, António Cunha, Aurélio J. C. Campilho
Expert Syst. Appl.5
2021 LNDb challenge on automatic lung cancer patient management
João Pedrosa, Guilherme Aresta, Carlos Ferreira 0006, Gurraj Atwal, Hady Ahmady Phoulady, Rongzhen Chen, Jiaoliang Li, Liansheng Wang 0002, Adrian Galdran, Abdelhamid Bouchachia, Krishna Chaitanya Kaluva, Kiran Vaidhya, Abhijith Chunduru, Sambit Tarai, Sai Prasad Pranav Nadimpalli, Suthirth Vaidya, Ildoo Kim, Alexandr G. Rassadin, Zhenhuan Tian, Zhongwei Sun, Yizhuan Jia, Xuejun Men, António Cunha, Aurélio J. C. Campilho
Medical Image Anal.25
2020 Automatic Lung Nodule Detection Combined With Gaze Information Improves Radiologists' Screening Performance
abstract
Early diagnosis of lung cancer via computed tomography can significantly reduce the morbidity and mortality rates associated with the pathology. However, searching lung nodules is a high complexity task, which affects the success of screening programs. Whilst computer-aided detection systems can be used as second observers, they may bias radiologists and introduce significant time overheads. With this in mind, this study assesses the potential of using gaze information for integrating automatic detection systems in the clinical practice. For that purpose, 4 radiologists were asked to annotate 20 scans from a public dataset while being monitored by an eye tracker device, and an automatic lung nodule detection system was developed. Our results show that radiologists follow a similar search routine and tend to have lower fixation periods in regions where finding errors occur. The overall detection sensitivity of the specialists was 0.67±0.07, whereas the system achieved 0.69. Combining the annotations of one radiologist with the automatic system significantly improves the detection performance to similar levels of two annotators. Filtering automatic detection candidates only for low fixation regions still significantly improves the detection sensitivity without increasing the number of false-positives.
Guilherme Aresta, Carlos Ferreira 0006, João Pedrosa, Teresa Araujo, João Rebelo, Eduardo Negrão, Margarida Morgado, António Cunha, Aurélio J. C. Campilho
IEEE J. Biomed. Health Informatics9
2019 An unsupervised metaheuristic search approach for segmentation and volume measurement of pulmonary nodules in lung CT scans
Elham Shakibapour, António Cunha, Guilherme Aresta, Ana Maria Mendonça, Aurélio J. C. Campilho
Expert Syst. Appl.2
2018 Deep Homography Based Localization on Videos of Endoscopic Capsules
Gil Pinheiro, Paulo Jorge Simões Coelho, Marta Salgado, Hélder P. Oliveira, António Cunha
BIBM5
2018 Convolutional Neural Network Architectures for Texture Classification of Pulmonary Nodules
Carlos Ferreira 0006, António Cunha, Ana Maria Mendonça, Aurélio J. C. Campilho
CIARP2
2014 ASL: a DSL for remote contact center agents
abstract
Altitude Scripting Language (ASL) is a Domain Specific Language (DSL) aimed at and using a syntax familiar to the contact center world, which in its current implementation, allows for agent scripts to be run remotely and presented within any modern web browser. This paper discusses the ASL language and interpreter as well and its most recent changes, architecture and challenges, as agents become remote and contact centers move towards the cloud paradigm.
Andre Carvalho, Susana Oliveira, Sandra Fernandes, António Cunha
SMC4