References of "Hoyoux, Thomas"
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See detailComputer vision systems for automatic analysis of face and eye images in specific applications of interpretation of facial expressions
Hoyoux, Thomas ULiege

Doctoral thesis (2017)

This thesis is about the computer vision-based automation of specific tasks of face perception, for specific applications where they are essential. These tasks, and the applications in which they are ... [more ▼]

This thesis is about the computer vision-based automation of specific tasks of face perception, for specific applications where they are essential. These tasks, and the applications in which they are automated, deal with the interpretation of facial expressions. Our first application of interest is the automatic recognition of sign language, as carried out via a chain of automatic systems that extract visual communication cues from the image of a signer, transcribe these visual cues to an intermediary semantic notation, and translate this semantic notation to a comprehensible text in a spoken language. For use within the visual cue extraction part of such a system chain, we propose a computer vision system that automatically extracts facial communication cues from the image of a signer, based on a pre-existing facial landmark point tracking method and its various robust refinements. With this system, our contribution notably lies in the fruitful use of this tracking method and its refinements within a sign language recognition system chain. We consider the facial communication cues extracted by our system as facial expressions with a specific interpretation useful to this application. Our second application of interest is the objective assessment of visual pursuit in patients with a disorder of consciousness. In the clinical practice, this delicate assessment is done by a clinician who manually moves a handheld mirror in front of the patient's face while simultaneously estimating the patient's ability to track this visual stimulus. This clinical setup is appropriate, but the assessment outcome was shown to be sensitive to the clinician's subjectivity. For use with a head-mounted device, we propose a computer vision system that attaches itself to the clinical procedure without disrupting it, and automatically estimates, in an objective way, the patient's ability to perform visual pursuit. Our system, combined with the use of a head-mounted device, therefore takes the form of an assisting technology for the clinician. It is based on the tracking of the patient's pupil and the mirror moved by the clinician, and the comparison of the obtained trajectories. All methods used within our system are simple yet specific instantiations of general methods, for the objective assessment of visual pursuit. We consider the visual pursuit ability extracted by our system as a facial expression with a specific interpretation useful to this application. To some extent, our third application of interest is the general-purpose automatic recognition of facial expression codes in a muscle-based taxonomic coding system. We do not actually provide any new computer vision system for this application. Instead, we consider a supervised classification problem relevant to this application, and we empirically compare the performance of two general classification approaches for solving this problem, namely hierarchical classification and standard classification ("flat" classification, in this comparative context). We also compare these approaches for solving a classification problem relevant to 3D shape recognition, as well as artificial classification problems we generate in a simulation framework of our design. Our contribution lies in the general theoretical conclusions we reach from our empirical study of hierarchical vs. flat classification, which are of interest for properly using hierarchical classification in vision-based recognition problems, for example for an application of facial expression recognition. [less ▲]

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See detailObjective drowsiness monitoring to assess fitness for duty
François, Clémentine ULiege; Hoyoux, Thomas ULiege; Langohr, Thomas ULiege et al

Poster (2016, September 16)

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See detailCan computer vision problems benefit from structured hierarchical classification?
Hoyoux, Thomas ULiege; Rodríguez-Sánchez, Antonio J.; Piater, Justus H.

in Machine Vision & Applications (2016)

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See detailTests of a new drowsiness characterization and monitoring system based on ocular parameters
François, Clémentine ULiege; Hoyoux, Thomas ULiege; Langohr, Thomas ULiege et al

in International Journal of Environmental Research and Public Health (2016)

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See detailCan computer vision problems benefit from structured hierarchical classification?
Hoyoux, Thomas ULiege; Rodríguez-Sánchez, Antonio J.; Piater, Justus H. et al

in Computer Analysis of Images and Patterns (2015)

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See detailTest of a new drowsiness monitoring system based on ocular parameters
François, Clémentine ULiege; Hoyoux, Thomas ULiege; Langohr, Thomas ULiege et al

Conference (2015, July 30)

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See detailTest of a new drowsiness monitoring system based on images of the eye
François, Clémentine ULiege; Langohr, Thomas ULiege; Hoyoux, Thomas ULiege et al

Conference (2015, March 24)

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See detailEnhancing gloss-based corpora with facial features using active appearance models
Schmidt, Christoph; Koller, Oscar; Ney, Hermann et al

in Proceedings of the Third International Symposium on Sign Language Translation and Avatar Technology (2013, October 19)

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See detailUsing viseme recognition to improve a sign language translation system
Schmidt, Christoph; Koller, Oscar; Ney, Hermann et al

in IWSLT 2013 Proceedings (2013)

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See detailRWTH-PHOENIX-Weather: a large vocabulary sign language recognition and translation corpus.
Forster, Jens; Schmidt, Christoph; Hoyoux, Thomas ULiege et al

in LREC 2012 Proceedings (2012)

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See detailFace and facial feature tracking for continuous sign language recognition
Hoyoux, Thomas ULiege

Diverse speeche and writing (2010)

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See detailVideo analysis for continuous sign language recognition
Piater, Justus ULiege; Hoyoux, Thomas ULiege; Du, Wei ULiege

in 4th Workshop on the Representation and Processing of Sign Languages: Corpora and Sign Language Technologies (2010)

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See detailSignspeak--understanding, recognition, and translation of sign languages
Dreuw, Philippe; Forster, Jens; Gweth, Yannick et al

in 4th Workshop on the Representation and Processing of Sign Languages: Corpora and Sign Language Technologies (2010)

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See detailSignSpeak -- Scientific Understanding and Vision-Based Technological Development for Continuous Sign Language Recognition and Translation
Dreuw, Philippe; Forster, Jens; Gweth, Yannick et al

in 4th Workshop on the Representation and Processing of Sign Languages: Corpora and Sign Language Technologies (2010)

Detailed reference viewed: 70 (6 ULiège)