Vassileios Balntas

dblp:155/3298 · also Vasileios Balntas · DBLP profile ↗
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18ranked-venue papers
8as first author
6since 2021 · last 2025
0000-0003-0667-1158ORCID · corroborated

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

Artificial intelligence and machine learning · 17 · 8 first-author · 5 since 2021Graphics, computer vision, multimedia, augmented reality and games · 15 · 6 first-author · 6 since 2021
YearPublicationVenuePosition
2025 Human-in-the-Loop Local Corrections of 3D Scene Layouts via Infilling
abstract
We present a novel human-in-the-loop approach to estimate 3D scene layout that uses human feedback from an egocentric standpoint. We study this approach through introduction of a novel local correction task, where users identify local errors and prompt a model to automatically correct them. Building on SceneScript, a state-of-the-art framework for 3D scene layout estimation that leverages structured language, we propose a solution that structures this problem as "infilling", a task studied in natural language processing. We train a multi-task version of SceneScript that maintains performance on global predictions while significantly improving its local correction ability. We integrate this into a human-in-the-loop system, enabling a user to iteratively refine scene layout estimates via a low-friction "one-click fix'' workflow. Our system enables the final refined layout to diverge from the training distribution, allowing for more accurate modelling of complex layouts.
Christopher Xie, Armen Avetisyan, Henry Howard-Jenkins, Yawar Siddiqui, Julian Straub, Richard A. Newcombe, Vassileios Balntas, Jakob J. Engel
ICCV7
2024 SceneScript: Reconstructing Scenes with an Autoregressive Structured Language Model
Armen Avetisyan, Christopher Xie, Henry Howard-Jenkins, Tsun-Yi Yang, Samir Aroudj, Suvam Patra, Fuyang Zhang, Duncan P. Frost, Luke Holland, Campbell Orme, Jakob J. Engel, Edward Miller 0001, Richard A. Newcombe, Vassileios Balntas
ECCV (61)14
2023 OrienterNet: Visual Localization in 2D Public Maps with Neural Matching
abstract
Humans can orient themselves in their 3D environments using simple 2D maps. Differently, algorithms for visual localization mostly rely on complex 3D point clouds that are expensive to build, store, and maintain over time. We bridge this gap by introducing OrienterNet, the first deep neural network that can localize an image with sub-meter accuracy using the same 2D semantic maps that humans use. OrienterNet estimates the location and orientation of a query image by matching a neural Bird's-Eye View with open and globally available maps from OpenStreetMap, enabling anyone to localize anywhere such maps are available. OrienterNet is supervised only by camera poses but learns to perform semantic matching with a wide range of map elements in an end-to-end manner. To enable this, we introduce a large crowd-sourced dataset of images captured across 12 cities from the diverse viewpoints of cars, bikes, and pedestrians. OrienterNet generalizes to new datasets and pushes the state of the art in both robotics and AR scenarios. The code is available at github.com/facebookresearch/OrienterNet.
Paul-Edouard Sarlin, Daniel DeTone, Tsun-Yi Yang, Armen Avetisyan, Julian Straub, Tomasz Malisiewicz, Samuel Rota Bulò, Richard A. Newcombe, Peter Kontschieder, Vassileios Balntas
CVPR10
2022 OoD-Pose: Camera Pose Regression From Out-of-Distribution Synthetic Views
abstract
In this paper, we address the problem of camera pose estimation in outdoor and indoor scenarios. We propose a relative pose regression method that can directly regress the camera pose from images with significantly higher accuracy than existing methods of the same class. We first investigate one of the main factors that limits the accuracy of relative pose regression, and then introduce a new approach that significantly improves the performance. Specifically, we propose a method to overcome the biased training data by a novel training technique. It generates poses, guided by a probability distribution of the training set, which are then used to synthesise new views for training. Lastly, we evaluate our approach on widely used benchmarks and show that it achieves significantly lower error compared to prior regression-based methods and retrieval techniques.
Tony Ng, Adrián López Rodríguez, Vassileios Balntas, Krystian Mikolajczyk
3DV3
2022 NinjaDesc: Content-Concealing Visual Descriptors via Adversarial Learning
abstract
In the light of recent analyses on privacy-concerning scene revelation from visual descriptors, we develop descriptors that conceal the input image content. In particular, we propose an adversarial learning framework for training visual descriptors that prevent image reconstruction, while maintaining the matching accuracy. We let a feature encoding network and image reconstruction network compete with each other, such that the feature encoder tries to impede the image reconstruction with its generated descriptors, while the reconstructor tries to recover the input image from the descriptors. The experimental results demonstrate that the visual descriptors obtained with our method significantly deteriorate the image reconstruction quality with minimal impact on correspondence matching and camera localization performance.
Tony Ng, Hyo Jin Kim 0004, Vincent T. Lee, Daniel DeTone, Tsun-Yi Yang, Tianwei Shen, Eddy Ilg, Vassileios Balntas, Krystian Mikolajczyk, Chris Sweeney
CVPR8
2021 Mitigating Reverse Engineering Attacks on Local Feature Descriptors
Deeksha Dangwal, Vincent T. Lee, Hyo Jin Kim 0004, Tianwei Shen, Meghan Cowan, Rajvi Shah, Caroline Trippel, Brandon Reagen, Timothy Sherwood, Vassileios Balntas, Armin Alaghi, Eddy Ilg
BMVC10
2020 D2D: Keypoint Extraction with Describe to Detect Approach
Yurun Tian, Vassileios Balntas, Tony Ng, Axel Barroso Laguna, Yiannis Demiris, Krystian Mikolajczyk
ACCV (3)2
2020 SOLAR: Second-Order Loss and Attention for Image Retrieval
Tony Ng, Vassileios Balntas, Yurun Tian, Krystian Mikolajczyk
ECCV (25)2
2020 HyNet: Learning Local Descriptor with Hybrid Similarity Measure and Triplet Loss
abstract
In this paper, we investigate how L2 normalisation affects the back-propagated descriptor gradients during training. Based on our observations, we propose HyNet, a new local descriptor that leads to state-of-the-art results in matching. HyNet introduces a hybrid similarity measure for triplet margin loss, a regularisation term constraining the descriptor norm, and a new network architecture that performs L2 normalisation of all intermediate feature maps and the output descriptors. HyNet surpasses previous methods by a significant margin on standard benchmarks that include patch matching, verification, and retrieval, as well as outperforming full end-to-end methods on 3D reconstruction tasks.
Yurun Tian, Axel Barroso Laguna, Tony Ng, Vassileios Balntas, Krystian Mikolajczyk
NeurIPS4
2020 $\mathbb {H}$H-Patches: A Benchmark and Evaluation of Handcrafted and Learned Local Descriptors
abstract
In this paper, a novel benchmark is introduced for evaluating local image descriptors. We demonstrate limitations of the commonly used datasets and evaluation protocols, that lead to ambiguities and contradictory results in the literature. Furthermore, these benchmarks are nearly saturated due to the recent improvements in local descriptors obtained by learning from large annotated datasets. To address these issues, we introduce a new large dataset suitable for training and testing modern descriptors, together with strictly defined evaluation protocols in several tasks such as matching, retrieval and verification. This allows for more realistic, thus more reliable comparisons in different application scenarios. We evaluate the performance of several state-of-the-art descriptors and analyse their properties. We show that a simple normalisation of traditional hand-crafted descriptors is able to boost their performance to the level of deep learning based descriptors once realistic benchmarks are considered. Additionally we specify a protocol for learning and evaluating using cross validation. We show that when training state-of-the-art descriptors on this dataset, the traditional verification task is almost entirely saturated.
Vassileios Balntas, Karel Lenc, Andrea Vedaldi, Tinne Tuytelaars, Jiri Matas, Krystian Mikolajczyk
IEEE Trans. Pattern Anal. Mach. Intell.1
2019 SOSNet: Second Order Similarity Regularization for Local Descriptor Learning
abstract
Despite the fact that Second Order Similarity (SOS) has been used with significant success in tasks such as graph matching and clustering, it has not been exploited for learning local descriptors. In this work, we explore the potential of \sos in the field of descriptor learning by building upon the intuition that a positive pair of matching points should exhibit similar distances with respect to other points in the embedding space. Thus, we propose a novel regularization term, named Second Order Similarity Regularization (SOSR), that follows this principle. By incorporating SOSR into training, our learned descriptor achieves state-of-the-art performance on several challenging benchmarks containing distinct tasks ranging from local patch retrieval to structure from motion. Furthermore, by designing a von Mises-Fischer distribution based evaluation method, we link the utilization of the descriptor space to the matching performance, thus demonstrating the effectiveness of our proposed SOSR. Extensive experimental results, empirical evidence, and in-depth analysis are provided, indicating that SOSR can significantly boost the matching performance of the learned descriptor.
Yurun Tian, Xin Yu 0002, Bin Fan 0001, Fuchao Wu, Huub Heijnen, Vassileios Balntas
CVPR6
2018 RelocNet: Continuous Metric Learning Relocalisation Using Neural Nets
Vassileios Balntas, Shuda Li, Victor Adrian Prisacariu
ECCV (14)1
2018 Binary Online Learned Descriptors
abstract
We propose a novel approach to generate a binary descriptor optimized for each image patch independently. The approach is inspired by the linear discriminant embedding that simultaneously increases inter and decreases intra class distances. A set of discriminative and uncorrelated binary tests is established from all possible tests in an offline training process. The patch adapted descriptors are then efficiently built online from a subset of features which lead to lower intra-class distances and thus, to a more robust descriptor. We perform experiments on three widely used benchmarks and demonstrate improvements in matching performance, and illustrate that per-patch optimization outperforms global optimization.
Vassileios Balntas, Lilian Tang, Krystian Mikolajczyk
IEEE Trans. Pattern Anal. Mach. Intell.1
2017 HPatches: A Benchmark and Evaluation of Handcrafted and Learned Local Descriptors
abstract
In this paper, a novel benchmark is introduced for evaluating local image descriptors. We demonstrate limitations of the commonly used datasets and evaluation protocols, that lead to ambiguities and contradictory results in the literature. Furthermore, these benchmarks are nearly saturated due to the recent improvements in local descriptors obtained by learning from large annotated datasets. To address these issues, we introduce a new large dataset suitable for training and testing modern descriptors, together with strictly defined evaluation protocols in several tasks such as matching, retrieval and verification. This allows for more realistic, thus more reliable comparisons in different application scenarios. We evaluate the performance of several state-of-the-art descriptors and analyse their properties. We show that a simple normalisation of traditional hand-crafted descriptors is able to boost their performance to the level of deep learning based descriptors once realistic benchmarks are considered. Additionally we specify a protocol for learning and evaluating using cross validation. We show that when training state-of-the-art descriptors on this dataset, the traditional verification task is almost entirely saturated.
Vassileios Balntas, Karel Lenc, Andrea Vedaldi, Krystian Mikolajczyk
CVPR1
2017 Pose Guided RGBD Feature Learning for 3D Object Pose Estimation
abstract
In this paper we examine the effects of using object poses as guidance to learning robust features for 3D object pose estimation. Previous works have focused on learning feature embeddings based on metric learning with triplet comparisons and rely only on the qualitative distinction of similar and dissimilar pose labels. In contrast, we consider the exact pose differences between the training samples, and aim to learn embeddings such that the distances in the pose label space are proportional to the distances in the feature space. However, since it is less desirable to force the pose-feature correlation when objects are symmetric, we discuss the use of weights that reflect object symmetry when measuring the pose distances. Furthermore, end-to-end pose regression is investigated and is shown to further boost the discriminative power of feature learning, improving pose recognition accuracies. Experimental results show that the features that are learnt guided by poses, are significantly more discriminative than the ones learned in the traditional way, outperforming state-of-the-art works. Finally, we measure the generalisation capacity of pose guided feature learning in previously unseen scenes containing objects under different occlusion levels, and we show that it adapts well to novel tasks.
Vassileios Balntas, Andreas Doumanoglou, Caner Sahin, Juil Sock, Rigas Kouskouridas, Tae-Kyun Kim 0001
ICCV1
2016 Learning local feature descriptors with triplets and shallow convolutional neural networks
Vassileios Balntas, Edgar Riba, Daniel Ponsa, Krystian Mikolajczyk
BMVC1
2015 BOLD - Binary online learned descriptor for efficient image matching
abstract
In this paper we propose a novel approach to generate a binary descriptor optimized for each image patch independently. The approach is inspired by the linear discriminant embedding that simultaneously increases inter and decreases intra class distances. A set of discriminative and uncorrelated binary tests is established from all possible tests in an offline training process. The patch adapted descriptors are then efficiently built online from a subset of tests which lead to lower intra class distances thus a more robust descriptor. A patch descriptor consists of two binary strings where one represents the results of the tests and the other indicates the subset of the patch-related robust tests that are used for calculating a masked Hamming distance. Our experiments on three different benchmarks demonstrate improvements in matching performance, and illustrate that per-patch optimization outperforms global optimization.
Vassileios Balntas, Lilian Tang, Krystian Mikolajczyk
CVPR1
2014 Improving Object Tracking with Voting from False Positive Detections
abstract
Context provides additional information in detection and tracking and several works proposed online trained trackers that make use of the context. However, the context is usually considered during tracking as items with motion patterns significantly correlated with the target. We propose a new approach that exploits context in tracking-by-detection and makes use of persistent false positive detections. True detection as well as repeated false positives act as pointers to the location of the target. This is implemented with a generalised Hough voting and incorporated into a state-of-the art online learning framework. The proposed method presents good performance in both speed and accuracy and it improves the current state of the art results in a challenging benchmark.
Vassileios Balntas, Lilian Tang, Krystian Mikolajczyk
ICPR1