Swathikiran Sudhakaran, Sergio Escalera, & Oswald Lanz. (2019). LSTA: Long Short-Term Attention for Egocentric Action Recognition. In 32nd IEEE Conference on Computer Vision and Pattern Recognition (pp. 9946–9955).
Abstract: Egocentric activity recognition is one of the most challenging tasks in video analysis. It requires a fine-grained discrimination of small objects and their manipulation. While some methods base on strong supervision and attention mechanisms, they are either annotation consuming or do not take spatio-temporal patterns into account. In this paper we propose LSTA as a mechanism to focus on features from spatial relevant parts while attention is being tracked smoothly across the video sequence. We demonstrate the effectiveness of LSTA on egocentric activity recognition with an end-to-end trainable two-stream architecture, achieving state-of-the-art performance on four standard benchmarks.
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Sergio Escalera, Alicia Fornes, Oriol Pujol, Alberto Escudero, & Petia Radeva. (2009). Circular Blurred Shape Model for Symbol Spotting in Documents. In 16th IEEE International Conference on Image Processing (pp. 1985–1988).
Abstract: Symbol spotting problem requires feature extraction strategies able to generalize from training samples and to localize the target object while discarding most part of the image. In the case of document analysis, symbol spotting techniques have to deal with a high variability of symbols' appearance. In this paper, we propose the Circular Blurred Shape Model descriptor. Feature extraction is performed capturing the spatial arrangement of significant object characteristics in a correlogram structure. Shape information from objects is shared among correlogram regions, being tolerant to the irregular deformations. Descriptors are learnt using a cascade of classifiers and Abadoost as the base classifier. Finally, symbol spotting is performed by means of a windowing strategy using the learnt cascade over plan and old musical score documents. Spotting and multi-class categorization results show better performance comparing with the state-of-the-art descriptors.
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Jose Manuel Alvarez, Ferran Diego, Joan Serrat, & Antonio Lopez. (2009). Automatic Ground-truthing using video registration for on-board detection algorithms. In 16th IEEE International Conference on Image Processing (pp. 4389–4392).
Abstract: Ground-truth data is essential for the objective evaluation of object detection methods in computer vision. Many works claim their method is robust but they support it with experiments which are not quantitatively assessed with regard some ground-truth. This is one of the main obstacles to properly evaluate and compare such methods. One of the main reasons is that creating an extensive and representative ground-truth is very time consuming, specially in the case of video sequences, where thousands of frames have to be labelled. Could such a ground-truth be generated, at least in part, automatically? Though it may seem a contradictory question, we show that this is possible for the case of video sequences recorded from a moving camera. The key idea is transferring existing frame segmentations from a reference sequence into another video sequence recorded at a different time on the same track, possibly under a different ambient lighting. We have carried out experiments on several video sequence pairs and quantitatively assessed the precision of the transformed ground-truth, which prove that our approach is not only feasible but also quite accurate.
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Angel Sappa, & Mohammad Rouhani. (2009). Efficient Distance Estimation for Fitting Implicit Quadric Surfaces. In 16th IEEE International Conference on Image Processing (3521–3524).
Abstract: This paper presents a novel approach for estimating the shortest Euclidean distance from a given point to the corresponding implicit quadric fitting surface. It first estimates the orthogonal orientation to the surface from the given point; then the shortest distance is directly estimated by intersecting the implicit surface with a line passing through the given point according to the estimated orthogonal orientation. The proposed orthogonal distance estimation is easily obtained without increasing computational complexity; hence it can be used in error minimization surface fitting frameworks. Comparisons of the proposed metric with previous approaches are provided to show both improvements in CPU time as well as in the accuracy of the obtained results. Surfaces fitted by using the proposed geometric distance estimation and state of the art metrics are presented to show the viability of the proposed approach.
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Carlo Gatta, & Petia Radeva. (2009). Bilateral Enhancers. In 16th IEEE International Conference on Image Processing (pp. 3161–3165).
Abstract: Ten years ago the concept of bilateral filtering (BF) became popular in the image processing community. The core of the idea is to blend the effect of a spatial filter, as e.g. the Gaussian filter, with the effect of a filter that acts on image values. The two filters acts on orthogonal domains of a picture: the 2D lattice of the image support and the intensity (or color) domain. The BF approach is an intuitive way to blend these two filters giving rise to algorithms that perform difficult tasks requiring a relatively simple design. In this paper we extend the concept of BF, proposing the bilateral enhancers (BE). We show how to design proper functions to obtain an edge-preserving smoothing and a selective sharpening. Moreover, we show that the proposed algorithm can perform edge-preserving smoothing and selective sharpening simultaneously in a single filtering.
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Santiago Segui, Laura Igual, & Jordi Vitria. (2010). Weighted Bagging for Graph based One-Class Classifiers. In 9th International Workshop on Multiple Classifier Systems (Vol. 5997, pp. 1–10). LNCS. Springer Berlin Heidelberg.
Abstract: Most conventional learning algorithms require both positive and negative training data for achieving accurate classification results. However, the problem of learning classifiers from only positive data arises in many applications where negative data are too costly, difficult to obtain, or not available at all. Minimum Spanning Tree Class Descriptor (MSTCD) was presented as a method that achieves better accuracies than other one-class classifiers in high dimensional data. However, the presence of outliers in the target class severely harms the performance of this classifier. In this paper we propose two bagging strategies for MSTCD that reduce the influence of outliers in training data. We show the improved performance on both real and artificially contaminated data.
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Dani Rowe, Ignasi Rius, Jordi Gonzalez, & Juan J. Villanueva. (2005). Robust Particle Filtering for Object Tracking.
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Maya Dimitrova, Ch. Roumenin, Siya Lozanova, David Rotger, & Petia Radeva. (2007). An Interface System Based on Multimodal Principle for Cardiological Diagnosis Assistance. In International Conference On Computer Systems And Technologies (Vol. IIIB.4, 1–6).
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Jose Ramirez Moreno, Juan R Revilla, Miguel Reyes, & Sergio Escalera. (2016). Validación del Software ADIBAS asociado al sensor Kinect de Microsoft para la evaluación de la posición corporal. In 4th Congreso WCPT-SAR.
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Craig Von Land, Ricardo Toledo, & Juan J. Villanueva. (1996). CARE: Computer Assisted Radiology Environment.
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Craig Von Land, Ricardo Toledo, & Juan J. Villanueva. (1996). TeleRegion: Tele-Applications for European Regions.
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Ekaterina Zaytseva, Santiago Segui, & Jordi Vitria. (2012). Sketchable Histograms of Oriented Gradients for Object Detection. In 17th Iberomerican Conference on Pattern Recognition (Vol. 7441, pp. 374–381). Springer Berlin Heidelberg.
Abstract: In this paper we investigate a new representation approach for visual object recognition. The new representation, called sketchable-HoG, extends the classical histogram of oriented gradients (HoG) feature by adding two different aspects: the stability of the majority orientation and the continuity of gradient orientations. In this way, the sketchable-HoG locally characterizes the complexity of an object model and introduces global structure information while still keeping simplicity, compactness and robustness. We evaluated the proposed image descriptor on publicly Catltech 101 dataset. The obtained results outperforms classical HoG descriptor as well as other reported descriptors in the literature.
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Jaume Garcia, Albert Andaluz, Debora Gil, & Francesc Carreras. (2010). Decoupled External Forces in a Predictor-Corrector Segmentation Scheme for LV Contours in Tagged MR Images. In 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (pp. 4805–4808).
Abstract: Computation of functional regional scores requires proper identification of LV contours. On one hand, manual segmentation is robust, but it is time consuming and requires high expertise. On the other hand, the tag pattern in TMR sequences is a problem for automatic segmentation of LV boundaries. We propose a segmentation method based on a predictorcorrector (Active Contours – Shape Models) scheme. Special stress is put in the definition of the AC external forces. First, we introduce a semantic description of the LV that discriminates myocardial tissue by using texture and motion descriptors. Second, in order to ensure convergence regardless of the initial contour, the external energy is decoupled according to the orientation of the edges in the image potential. We have validated the model in terms of error in segmented contours and accuracy of regional clinical scores.
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Arnau Baro, Jialuo Chen, Alicia Fornes, & Beata Megyesi. (2019). Towards a generic unsupervised method for transcription of encoded manuscripts. In 3rd International Conference on Digital Access to Textual Cultural Heritage (pp. 73–78).
Abstract: Historical ciphers, a special type of manuscripts, contain encrypted information, important for the interpretation of our history. The first step towards decipherment is to transcribe the images, either manually or by automatic image processing techniques. Despite the improvements in handwritten text recognition (HTR) thanks to deep learning methodologies, the need of labelled data to train is an important limitation. Given that ciphers often use symbol sets across various alphabets and unique symbols without any transcription scheme available, these supervised HTR techniques are not suitable to transcribe ciphers. In this paper we propose an un-supervised method for transcribing encrypted manuscripts based on clustering and label propagation, which has been successfully applied to community detection in networks. We analyze the performance on ciphers with various symbol sets, and discuss the advantages and drawbacks compared to supervised HTR methods.
Keywords: A. Baró, J. Chen, A. Fornés, B. Megyesi.
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Ozan Caglayan, Adrien Bardet, Fethi Bougares, Loic Barrault, Kai Wang, Marc Masana, et al. (2018). LIUM-CVC Submissions for WMT18 Multimodal Translation Task. In 3rd Conference on Machine Translation.
Abstract: This paper describes the multimodal Neural Machine Translation systems developed by LIUM and CVC for WMT18 Shared Task on Multimodal Translation. This year we propose several modifications to our previou multimodal attention architecture in order to better integrate convolutional features and refine them using encoder-side information. Our final constrained submissions
ranked first for English→French and second for English→German language pairs among the constrained submissions according to the automatic evaluation metric METEOR.
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