Comfort-driven disparity adjustment for stereoscopic video

Pixel disparity—the offset of corresponding pixels between left and right views—is a crucial parameter in stereoscopic three-dimensional (S3D) video, as it determines the depth perceived by the human visual system (HVS). Unsuitable pixel disparity distribution throughout an S3D video may lead to visual discomfort. We present a unified and extensible stereoscopic video disparity adjustment framework which improves the viewing experience for an S3D video by keeping the perceived 3D appearance as unchanged as possible while minimizing discomfort. We first analyse disparity and motion attributes of S3D video in general, then derive a wide-ranging visual discomfort metric from existing perceptual comfort models. An objective function based on this metric is used as the basis of a hierarchical optimisation method to find a disparity mapping function for each input video frame. Warping-based disparity manipulation is then applied to the input video to generate the output video, using the desired disparity mappings as constraints. Our comfort metric takes into account disparity range, motion, and stereoscopic window violation; the framework could easily be extended to use further visual comfort models. We demonstrate the power of our approach using both animated cartoons and real S3D videos

Attention-Aware Disparity Control in interactive environments

Cataloged from PDF version of article.Our paper introduces a novel approach for controlling stereo camera parameters in interactive 3D environments in a way that specifically addresses the interplay of binocular depth perception and saliency of scene contents. Our proposed Dynamic Attention-Aware Disparity Control (DADC) method produces depth-rich stereo rendering that improves viewer comfort through joint optimization of stereo parameters. While constructing the optimization model, we consider the importance of scene elements, as well as their distance to the camera and the locus of attention on the display. Our method also optimizes the depth effect of a given scene by considering the individual user’s stereoscopic disparity range and comfortable viewing experience by controlling accommodation/convergence conflict. We validate our method in a formal user study that also reveals the advantages, such as superior quality and practical relevance, of considering our method.© Springer-Verlag Berlin Heidelberg 2013

Methods for reducing visual discomfort in stereoscopic 3D: A review

This work was supported by the EPSRC Grant EP/M01469X/1, “Geometric Evaluation of Stereoscopic Video”

Outils logiciels temps réel pour l'assistance à la production stéréoscopique 3D

L'histoire du cinéma 3D est presque aussi longue que celle du cinéma 2D. Toutefois, ce n'est qu'avec l'utilisation des médias numériques que la commercialisation du contenu stéréoscopique 3D s'est concrétisée. Puisque la production stéréoscopique 3D nécessite l'utilisation de deux caméras, il est nécessaire de correctement ajuster celles-ci afin de produire du contenu pouvant être visualisé sans inconfort, tout en reproduisant adéquatement les caractéristiques du système visuel humain permettant la perception en profondeur. Les outils d'assistance à l'ajustement des caméras stéréoscopiques étant coûteux, la production de contenu stéréoscopique est généralement réservée aux utilisateurs expérimentés ou ayant des moyens financiers suffisants. Afin de rendre disponible l'utilisation et l'amélioration de cette technologie, il serait pertinent de fournir des outils gratuits et libres de droit. Puisqu'il existe des bibliothèques logicielles libres pour le traitement d'images stéréoscopiques appliqué au domaine de la reconstruction 3D, ce projet cherche à évaluer la possibilité d'adapter ces algorithmes pour le développement d'outils logiciels temps réel d'assistance à la production de contenu stéréoscopique. Pour ce faire, la détection et la correspondance de points caractéristiques sont utilisés afin de déterminer l'alignement relatif des caméras par l'estimation de la géométrie épipolaire. Les problèmes d'alignement sont par la suite corrigés par la rectification numérique des images. Afin d'obtenir une rectification stable en temps réel, les résultats montrent que des améliorations doivent être apportées aux algorithmes d'alignement et de rectification des images: 1) l'utilisation d'un détecteur de points caractéristiques alternatif non-propriétaire permettrait une meilleure performance; 2) l'utilisation d'un algorithme alternatif pour l'estimation robuste de l'alignement des caméras permettrait une estimation sans avoir à déterminer de paramètres de façon empirique; 3) l'utilisation d'un filtre de Kalman serait nécessaire pour une rectification stable des images lors d'une séquence vidéo. Le projet vise à l'intégration des techniques et de leurs améliorations dans une bibliothèque logicielle à code source ouvert, OpenS3D. Les fonctionnalités intégrées dans OpenS3D sont la visualisation de contenu stéréoscopique, les calculs pour l'assistance à l'alignement des caméras, la rectification numérique des images, l'analyse des profondeurs perçues pour une scène capturée. Toutes les fonctionnalités sont disponibles en temps réel à partir de l'interface utilisateur d'OpenS3D. Puisque les améliorations apportées aux techniques de calcul d'alignement des caméras permettent d'obtenir une estimation stable et cohérente au niveau temporel, cette estimation pourrait être directement utilisée afin de corriger les erreurs d’alignement de façon automatique. Une automatisation des paramètres des caméras permettrait par exemple de filmer des scènes 3D à partir de robots mobiles. De plus, des techniques supplémentaires pourraient être ajoutées au logiciel telles que l'analyse de rivalités rétiniennes pour les différences de couleur, de luminosité ou de reflets lumineux

Crosstalk in stereoscopic displays: A review

Crosstalk, also known as ghosting or leakage, is a primary factor in determining the image quality of stereoscopic three dimensional (3D) displays. In a stereoscopic display, a separate perspective view is presented to each of the observer’s two eyes in order to experience a 3D image with depth sensation. When crosstalk is present in a stereoscopic display, each eye will see a combination of the image intended for that eye, and some of the image intended for the other eye—making the image look doubled or ghosted. High levels of crosstalk can make stereoscopic images hard to fuse and lack fidelity, so it is important to achieve low levels of crosstalk in the development of high-quality stereoscopic displays. Descriptive and mathematical definitions of these terms are formalized and summarized. The mechanisms by which crosstalk occurs in different stereoscopic display technologies are also reviewed, including micropol 3D liquid crystal displays (LCDs), autostereoscopic (lenticular and parallax barrier), polarized projection, anaglyph, and time-sequential 3D on LCDs, plasma display panels and cathode ray tubes. Crosstalk reduction and crosstalk cancellation are also discussed along with methods of measuring and simulating crosstalk

Perceptually driven stereoscopic camera control in 3D virtual environments

Ankara : The Department of Computer Engineering and the Graduate School of Engineering and Science of Bilkent University, 2013.Thesis (Master's) -- Bilkent University, 2013.Includes bibliographical references leaves 56-59.Depth notion and how to perceive depth have long been studied in the eld of psychology, physiology, and even art. Human visual perception enables to perceive spatial layout of the outside world by using visual depth cues. Binocular disparity among these depth cues, is based on the separation between two di erent views that are observed by two eyes. Disparity concept constitutes the base of the construction of the stereoscopic vision. Emerging technologies try to replicate binocular disparity principles in order to provide 3D illusion and stereoscopic vision. However, the complexity of applying the underlying principles of 3D perception, confronted researchers the problem of wrongly produced stereoscopic contents. It is still a great challenge to give realistic but also comfortable 3D experience. In this work, we present a camera control mechanism: a novel approach for disparity control and a model for path generation. We try to address the challenges of stereoscopic 3D production by presenting comfortable viewing experience to users. Therefore, our disparity system approaches the accommodation/convergence con- ict problem, which is the most known issue that causes visual fatigue in stereo systems, by taking objects' importance into consideration. Stereo camera parameters are calculated automatically with an optimization process. In the second part of our control mechanism, the camera path is constructed for a given 3D environment and scene elements. Moving around important regions of objects is a desired scene exploration task. In this respect, object saliencies are used for viewpoint selection around scene elements. Path structure is generated by using linked B ezier curves which assures to pass through pre-determined viewpoints. Though there is considerable amount of research found in the eld of stereo creation, we believe that approaching this problem from scene content aspect provides a uniquely promising experience. We validate our assumption with user studies in which our method and existing two other disparity control models are compared. The study results show that our method shows superior results in quality, depth, and comfort.Kevinç, Elif BengüM.S

Attention-aware disparity control in interactive environments

Our paper introduces a novel approach for controlling stereo camera parameters in interactive 3D environments in a way that specifically addresses the interplay of binocular depth perception and saliency of scene contents. Our proposed Dynamic Attention-Aware Disparity Control (DADC) method produces depth-rich stereo rendering that improves viewer comfort through joint optimization of stereo parameters. While constructing the optimization model, we consider the importance of scene elements, as well as their distance to the camera and the locus of attention on the display. Our method also optimizes the depth effect of a given scene by considering the individual user's stereoscopic disparity range and comfortable viewing experience by controlling accommodation/convergence conflict. We validate our method in a formal user study that also reveals the advantages, such as superior quality and practical relevance, of considering our method. © 2013 Springer-Verlag Berlin Heidelberg