Motion Parallax

This report explores the phenomenon of motion parallax-a monocular depth cue-and examines its application in Buddhist walking meditation practices, particularly the teachings attributed to the Buddha over 2,500 years ago. Additionally, the report analyzes a personal observation from cycling, where focusing on the road ahead reduces perceived exertion during a climb. The convergence of these insights from psychology, Buddhism, and personal experience underscores the profound understanding of human perception and mindfulness.

We describe a new interactive system for 3D design review, built to exploit the visual perception cue of motion parallax, in order to enhance shape perception and aesthetic evaluation. Traditional CAD applications typically use "bookmarked" static views for design evaluation. In our system, we replace static views with moving "shots" interspersed with cinematic visual transitions. Furthermore, users can access shots by picking object features on the 3D model, which invokes a spatial search over all shots, selects the ones deemed relevant to the feature, and plays back those shots. In this paper we describe the rationale behind this system, the main components, the implementation of the search technique, and the initial user evaluation of the system.

Conventional multifocal displays deliver effective monocular focus cues but lack sufficient motion parallax, while multi-view displays offer motion parallax with no monocular focus cues. To overcome these limitations, we propose a system that leverages the benefit of viewpoint generation and the focus-tunable lens (FTL) to support both motion parallax and accommodation cues in one system. Experimental results demonstrate that the proposed setup successfully delivers full-resolution images with support for both depth cues, providing a more realistic visual experience. A compact design, with experimental results demonstrating its effectiveness, is also introduced to further enhance the system's compactness.

In order for an unmanned aerial vehicle (UAV) to safely fly close to the ground, it must be capable of detecting and avoiding obstacles in its flight path. From a single camera on the UAV, the 3D structure of its surrounding environment, including any obstacles, can be estimated from motion parallax using a technique called structure from motion. Most structure from motion algorithms attempt to reconstruct the 3D structure of the environment from a single optical flow value at each feature point. We present a novel method for calculating structure from motion that does not require a precise calculation of optical flow at each feature point. Due to the effects of image noise and the aperture problem, it may be impossible to accurately calculate a single optical flow value at each feature point. Instead we may only be able to calculate a set of likely optical flow values and their associated probabilities or an optical flow probability distribution. Using this probability distribution, a more robust method for calculating structure from motion is developed. This method is being developed for use on a UAV to detect obstacles, but it can be used on any vehicle where obstacle avoidance is needed.

Computer graphics is confined chiefly to flat images. Images may look three-dimensional (3D), and sometimes create the illusion of 3D when displayed, for example, on a stereoscopic display [16, 13, 12]. Nevertheless, when viewing an image on most display systems, the human visual system (HVS) sees a flat plane of pixels. Volumetric displays can create a 3D computer graphics image, but fail to provide many visual depth cues (e.g. shading texture gradients) and cannot provide the powerful depth cue of overlap (occlusion). Discrete parallax displays (such as lenticular displays) promise to create 3D images with all of the depth cues, but are limited by achievable resolution. Only a real-time electronic holographic ("holovideo") display [11, 6, 8, 7, 9, 21, 22, 20, 2] can create a truly 3D computer graphics image with all of the depth cues (motion parallax, ocular accommodation, occlusion, etc.) and resolution sufficient to provide extreme realism [13]. Holovideo displays prom...

Resumo-Teleconferência e outras aplicac ¸ões de vídeo em 3D têm se tornado de grande interesse. Além de displays estéreo, para obter um efeito de vídeo 3D realístico com ponto de vista livre (FVV) é necessário prover paralaxe de movimento. Uma das formas mais eficientes de sintetizar FVV de imagens naturais é aplicar renderizac ¸ão baseada em imagens, isto é, basear a imagem sintética em vídeos tomados de diferentes posic ¸ões em relac ¸ão à cena. Uma nova abordagem para codificac ¸ão de vídeo multiview foi proposta recentemente e mostrou que codificando cada macrobloco de cada imagem com um passo de quantizac ¸ão (QP) apropriado pode-se melhorar a taxa de compressão em até 2X. Os QPs utilizados para obter tal melhoramento são escolhidos baseados em uma regra experimental, que leva em considerac ¸ão os pesos da contribuic ¸ão de cada pixel na imagem sintética final. Nesse artigo, deriva-se o mapeamento ótimo dos QPs para um codec semelhante. Mostra-se então que o mapeamento anteriormente proposto é otimo para uma fonte Gaussiana, e indica-se o mapeamento ótimo para uma fonte genérica.

In this paper, a novel algorithm for creating virtual indoor environments is described. First, a panoramic mosaic is generated from a series of photos taken with a camera rotates along a horizontal axis. Then, from the panoramic mosaic image, a non-...

This paper describes a hardware system and the underlying algorithms that were developed for realtime stereoscopic videoconferencing with viewpoint adaptation within the European PANORAMA project. The goal was to achieve a true telepresence illusion for the remote partners. For this purpose, intermediate views at arbitrary positions must be synthesized from the views of a stereoscopic camera system with rather large baseline. The actual viewpoint is adapted according to the head position of the viewer, such that the impression of motion parallax is produced. The whole system consists of a disparity estimator, stereoscopic MPEG-2 encoder, disparity encoder and multiplexer at the transmitter side, and a demultiplexer, disparity decoder, MPEG-2 decoder and

Background: Surface lightness perception is affected by scene interpretation. There is some experimental evidence that perceived lightness under bi-ocular viewing conditions is different from perceived lightness in actual scenes but there are also reports that viewing conditions have little or no effect on perceived color. We investigated how mixes of depth cues affect perception of lightness in three-dimensional rendered scenes containing strong gradients of illumination in depth. Methodology/Principal Findings: Observers viewed a virtual room (4 m width65 m height617.5 m depth) with checkerboard walls and floor. In four conditions, the room was presented with or without binocular disparity (BD) depth cues and with or without motion parallax (MP) depth cues. In all conditions, observers were asked to adjust the luminance of a comparison surface to match the lightness of test surfaces placed at seven different depths (8.5-17.5 m) in the scene. We estimated lightness versus depth profiles in all four depth cue conditions. Even when observers had only pictorial depth cues (no MP, no BD), they partially but significantly discounted the illumination gradient in judging lightness. Adding either MP or BD led to significantly greater discounting and both cues together produced the greatest discounting. The effects of MP and BD were approximately additive. BD had greater influence at near distances than far. Conclusions/Significance: These results suggest the surface lightness perception is modulated by three-dimensional perception/interpretation using pictorial, binocular-disparity, and motion-parallax cues additively. We propose a two-stage (2D and 3D) processing model for lightness perception.

The motion of objects during motion parallax can be decomposed into 2 observer-relative components: translation and rotation. The depth ratio of objects in the visual field is specified by the inverse ratio of their angular displacement (from translation) or equivalently by the inverse ratio of their rotations. Despite the equal mathematical status of these 2 information sources, it was predicted that observers would be far more sensitive to the translational than rotational component. Such a differential sensitivity is implicitly assumed by the computer graphics technique billboarding, in which 3-dimensional (3-D) objects are drawn as planar forms (i.e., billboards) maintained normal to the line of sight. In 3 experiments, observers were found to be consistently less sensitive to rotational anomalies. The implications of these findings for kinetic depth effect displays and billboarding techniques are discussed.

When human subjects are presented with visual displays consisting of random dots moving sideways at different velocities, they perceive transparent surfaces, moving in the same direction but located at different distances from themselves. They perceive depth from motion parallax, without any additional cues to depth, such as relative size, occlusion or binocular disparity. Simultaneously, large-field visual motion triggers compensatory eye movements which tend to offset such motion, in order to stabilize the visual image of the environment. In a series of experiments, we investigated how such reflexive eye movements are controlled by motion parallax displays, that is, in a situation where a complete stabilization of the visual image is never possible. Results show that optokinetic nystagmus, and not merely active visual pursuit of singular elements, is triggered by such displays. Prior to the detection of depth from motion parallax, eye tracking velocity is equal to the average velocity of the visual image. After detection, eye tracking velocity spontaneously matches the slowest velocity in the visual field, but can be controlled by attentional factors. Finally, for a visual stimulation containing more than three velocities, subjects are no longer able to perceptually dissociate between different surfaces in depth, and eye tracking velocity remains equal to the average velocity of the visual image. These data suggest that, in the presence of flow fields containing motion parallax, optokinetic eye movements are modulated by perceptual and attentional factors. 01997 Elsevier Science Ltd.

We propose a new incremental motion estimation algorithm to deal with long image sequences. It applies to a sliding window of triplets of images, but unlike previous approaches, which rely on point matches across three or more views, we also use those points shared only by two views. This is important because matches between two views are more common than those across more views. The problem is formulated as a series of local bundle adjustments in such a way that the estimated camera motions in the whole sequence are consistent with each other. Two implementations are described. The first is an exact one, which, based on the observation of the sparse structure of the adjustment network, embeds the optimization of 3D structure parameters within the optimization of the camera pose parameters. This optimization embedding considerably reduces the minimization complexity. The second is a mathematical procedure which transforms the original problem involving both 3D structure and pose parameters into a much smaller one, a minimization over just the camera's pose parameters. This leads to an even higher computational gain. Because we make full use of local image information, our technique is more accurate than previous incremental techniques, and is very close to, and considerably faster than, global bundle adjustment. Experiments with both synthetic and real data have been conducted to compare the proposed technique with other techniques, and have shown our technique to be clearly superior.

With the release of new head-mounted displays (HMDs) and new omni-directional capture systems, 360-degree video is one of the latest and most powerful trends in immersive media, with an increasing potential for the next decades. However, especially creating 360-degree content in 3D is still an error-prone task with many limitations to overcome. This paper describes the critical aspects of 3D content creation for 360-degree video. In particular, conflicts of depth cues and binocular rivalry are reviewed in detail, as these cause eye fatigue, headache, and even nausea. Both the reasons for the appearance of the conflicts and how to detect some of these conflicts by objective image analysis methods are detailed in this paper. The latter is the main contribution of this paper and part of long-term research roadmap of the authors in order to provide a comprehensive framework for artifact detection and correction in 360-degree videos. Then, experimental results are demonstrating the perfo...

Volumetric displays permit electronically processed images to be depicted within a transparent physical volume and enable a range of cues to depth to be inherently associated with image content. Further, images can be viewed directly by multiple simultaneous observers who are able to change vantage positions in a natural way. On the basis of research to date, we assume that the technologies needed to implement useful volumetric displays able to support translucent image formation are available and so primarily focus on other issues that have impeded the broad commercialization and application of this display paradigm. This is of particular relevance given the recent resurgence of interest in developing commercially viable, general purpose, volumetric systems. We particularly consider image and display characteristics, usability issues and identify several advantageous attributes that need to be exploited in order to effectively capitalize on this display modality.

We propose a real-time stereoscopic image converter that can generate stereoscopic images with different perspective depth using motion parallax from a 2-D image. The stereoscopic image is generated by computing the motion parallax between two adjacent 2-D images using the proposed method for motion detection, region segmentation and depth map generation. We have compared the stereoscopic depth of the proposed method with that of the conventional method. The proposed converter is designed and implemented by using a FPGA and verified by evaluating the field-sequential stereoscopic image on a TV. This converter can automatically produce a realistic 3-D effect regardless of the direction and velocity of a moving object in the 2-D image 1 .

An image interpolator with image improvement is proposed and implemented for FPD(F1at Panel Display) in this paper. We propose the adaptive pseudomedian filter for the interpolation of images and the real-time contrast controller for image improvement. The proposed interpolation algorithm is based on a pseudomedian filter and uses transposed sub-windows according to the correlation of pixels in the image. The proposed contrast controller uses improved histogram stretching methods and does not require field and frame memory for processing the pixels. The operation of the proposed method has been verified and designed using computer simulation and VHDL. The proposed method achieves better performance than the others from the poht of view of the edge and local characteristics.

The selection and manipulation of 3D content in desktop virtual environments is commonly achieved with 2D mouse cursor-based interaction. However, by interacting with image-based techniques we introduce a conflict between the 2D space in which the 2D cursor lays and the 3D content. For example, the 2D mouse cursor does not provide any information about the depth of the selected objects. In this situation, the user has to rely on the depth cues provided by the virtual environment, such as perspective deformation, shading and shadows. In this paper, we explore new metaphors to improve the depth perception when interacting with 3D content. Our approach focus on the usage of 3D cursors controlled with 2D input devices (the Hand Avatar and the Torch) and a pseudo-motion parallax effect. The additional depth cues provided by the visual feedback of the 3D cursors and the motion parallax are expected to increase the users' depth perception of the environment. The evaluation of proposed techniques showed that users' depth perception was significantly increased. Users were able to better judge the depth ordering of virtual environment. Although 3D cursors showed a decrease of selection performance, it is compensated by the increased depth perception.

The ‘reverse-perspective’ illusion entails the apparent motion of a stationary scene painted in relief and containing misleading depth cues. We have found that, using prism goggles to induce horizontal or vertical visual-field reversals, the illusory motion is greatly reduced or eliminated in the direction for which the goggles reverse the visual field. We argue that the illusion is a consequence of the observer's inability to reconcile changes in visual information due to body movement with implicit knowledge concerning anticipated changes. As such, the reverse-perspective illusion may prove to be useful in the study of the integration of linear perspective and motion parallax information.

Multiple views of a scene, obtained from cameras positioned at distinct viewpoints, can provide a viewer with the benefits of added realism, selective viewing, and improved scene understanding. The importance of these signals is evidenced by the recently proposed Multi-View Profile (MVP) extension to the MPEG-2 video compression standard, and their explicit incorporation into the future MPEG-4 standard. However, multi-view compression implementations typically rely on single-view image sequence model assumptions. We hypothesize (and demonstrate) that impressive system bandwidth reduction can be achieved by utilizing displacement vector field and image intensity models tuned to the special characteristics of multi-view video signals. This thesis focuses on the predictive coding of non-periodic, i.e., arbitrary, multi-view video signals for the applications of simulated motion parallax and viewer-specified degree of stereoscopy. To facilitate their practical use, we desire algorithms that are applicable to the common waveform-based, hybrid encoder framework, which consists of a frame-based prediction followed by residual encoding. Three novel techniques are developed, which respectively improve the processes of framebased prediction, residual encoding, and viewpoint interpolation. These are: I would like to thank my co-advisors, Angel Jordan and Mel Siegel, for their support and guidance throughout the course of this work. I am indebted to them not only for their numerous ideas and suggestions, but also for the freedom they gave me to explore topics truly interesting to me. I would also like to thank Siu-Wai Wu and José Moura for participating on my thesis committee. Their advice and comments undoubtedly improved the quality of this thesis. I extend special thanks to the members of the Advanced Video Display Systems group:

Free-viewpoint rendering has always been one of the key motivations of image-based rendering and has broad application prospects in the field of virtual reality and augmented reality (VR/AR). The existing methods mainly adopt the traditional image-based rendering or learning-based frameworks, which have limited viewpoint freedom and poor time performance. In this paper, the cube surface light field is utilized to encode the scenes implicitly, and an interactive free-viewpoint rendering method is proposed to solve the above two problems simultaneously. The core of this method is a pure light ray-based representation using the cube surface light field. Using a fast single-layer ray casting algorithm to compute the light ray’s parameters, the rendering is achieved by a GPU-based three-dimensional (3D) compressed texture mapping that converts the corresponding light rays to the desired image. Experimental results show that the proposed method can real-time render the novel views at arbi...

Small digital video cameras have become increasingly common, appearing on portable consumer devices such as cellular phones. The widespread use of video-conferencing, however, is limited in part by the lack of bandwidth available on such devices. Also, videoconferencing can produce feelings of discomfort in conversants due to a lack of co-presence. Current techniques to increase co-presence are not practical in the consumer market due to the costly and elaborate equipment required (such as stereoscopic displays and multicamera arrays). To address these issues, this paper describes a real-time, full frame-rate video-conferencing system that provides simulated threedimensionality via motion parallax in order to achieve a higher level of co-presence. The system uses a deformable 3D face model to track and re-synthesize each user's face using only a single monocular camera, so that only the (few tens of) parameters of the model need be transferred for each frame. This both provides motiontracking for the simulated 3D experience and reduces the bandwidth requirements of the video-conference to the order of a few hundred bytes per frame. Bandwidth and processor usage for the algorithms are reported. Possible implications and applications of this technology are also discussed.

The Panoptic camera is an omnidirectional multi-aperture visual system which is realized by mounting multiple imaging sensors on a hemispherical frame. In this chapter, we will present a novel distributed and parallel implementation of the real-time omnidirectional vision reconstruction algorithm of the Panoptic Camera, for camera modules with processing, memory and interconnectivity features. A methodology for the arrangement of camera modules with interconnectivity feature into a target interconnection network topology will be introduced. A unique custom-made multiple-FPGA hardware platform designed for the implementation of an interconnected network of a 49 camera prototype Panoptic system will be explained. A novel way to represent the omnidirectional data obtained from the Panoptic Camera and real-time high dynamic range (HDR) video application which is realized by the system will be presented.. .

We introduce a mobile system for high resolution panoramic image creation. In our system the user can rotate the camera arbitrarily and see the preview panorama in real-time. The system automatically captures high resolution images and generates a high-quality result with unlimited viewing angle. We employ a coarse-to-fine method for high-quality registration, and a seam-finding method to remove the ghosting effect due to moving objects. The proposed system has been tested on several types of camera phones, and the tests reveal that the system can efficiently provide a high-quality panoramic image in spite of the low computational power and memory available in such devices.

Three-dimensional objects suffer from inaccuracies in the format of computational representation and artistic drawing, losing visual acuity. On the other hand, photographs offer visual acuity, but they are not interactive, that is, they do not offer the possibility of changing the perspective of visualization as a three-dimensional model does. Thus, we have created a device capable of scanning a real object, allowing for the production of interactive contents and visual acuity. In addition, the model created allows stereoscopic visualization, that is, with a notion of depth. We produced a learning object from the scans of a real object, assessed by teachers and students who work at medium, technical, and higher school levels. The interactive stereoscopic learning object with visual acuity seems promising for the responses to a questionnaire and interviews showed it motivated teachers and students due to its more realistic visualization and rich details. By allowing the visualization...

One way to provide realistic immersive VR content relies on producing high-quality panoramic videos. These videos are usually produced using multiple cameras with different optical centers and which may not be perfectly synchronized This results in spatial and temporal artifact, even though the blending algorithm strives to reduce them. In this paper, we devise a method that detects potential visual artifacts, based on existing view synthesis quality metrics. The method works by computing pair-wise quality at each blending step and fusing them to produce a global map of potential errors. To get a more accurate prediction, we develop a mask that is then applied to the error map and therefore accentuates the defects on the blending cutting line. Results show that the calculated distortion map succeeds to identify visual artifacts in panoramas which can help design better solutions to this problem in the future.

We present the results of our second radial velocity (RV) monitoring campaign, carried out with the Échelle spectrograph FLECHAS at the University Observatory Jena in the course of the Großschwabhausen binary survey between December 2016 and June 2018. The aim of this project is to obtain precise RV measurements for spectroscopic binary stars in order to redetermine, verify, improve, and constrain their Keplerian orbital solutions. In this paper, we describe the observations, data reduction, and analysis and present the results of this project. In total, we have taken 721 RV measurements of 11 stars and derived well-determined orbital solutions for nine systems (seven single-and two double-lined spectroscopic binaries) with periods in the range between 2 and 70 days. In addition, we could rule out the orbital solutions for the previously classified spectroscopic binary systems HIP 107136 and HIP 107533, whose radial velocities are found to be constant on the km s −1-level over a span of time of more than 500 days. In the case of HIP 2225, a significant change of its systematic velocity is detected between our individual observing epochs, indicating the presence of an additional companion, which is located on a wider orbit in this system.

Equirectangular panoramas are popular tools for achieving 360 degree immersed viewing experiences. A panorama captures a scene from one point and panoramic viewers allow the user to control the viewing direction, but the viewer is not allowed to move around. This study proposes a strategy for transforming equirectangular panoramic images with the effect of moving freely in three dimensions. The strategy assumes that the panorama is an enclosed space comprising a flat ground and flat vertical walls. A equirectuangular Hough transform is proposed for detecting the boundaries of the respective planes. The panoramic image is then decomposed into the respective planes, the viewing point is translated and a new panoramic image based on the new viewing position is composed. Preliminary proof of concept test shows that the strategy allows free translation within simple panoramic images.

We describe a new interactive system for 3D design review, built to exploit the visual perception cue of motion parallax, in order to enhance shape perception and aesthetic evaluation. Traditional CAD applications typically use "bookmarked" static views for design evaluation. In our system, we replace static views with moving "shots" interspersed with cinematic visual transitions. Furthermore, users can access shots by picking object features on the 3D model, which invokes a spatial search over all shots, selects the ones deemed relevant to the feature, and plays back those shots. In this paper we describe the rationale behind this system, the main components, the implementation of the search technique, and the initial user evaluation of the system.

To support multiperspective and stereographic image display systems intended for multiuser applications, we have developed two integrated multiuser multiperspective stereographic browsers, respectively featuring IBR-generated egocentric and CG exocentric perspectives. The first one described, “VR4U2C” (‘virtual reality for you to see’), uses Apple's QuickTime VR technology and the Java programming language together with the support of the QuickTime for Java library. This unique QTVR browser allows coordinated display of multiple views of a scene or object, limited only by the size and number of monitors or projectors assembled around or among users (for panoramas or turnoramas) in various viewing locations. The browser also provides a novel solution to limitations associated with display of QTVR imagery: its multinode feature provides interactive stereographic QTVR (dubbed SQTVR) to display dynamically selected pairs of images exhibiting binocular parallax, the stereoscopic dept...

previous research by our research group introduced the idea of stereographic panoramic browsing via our" VR4U2C" client, subsequently extended to allow not only zooming, a simple scaling of the image, but also dollying, allowing limited viewpoint motion—enabled by multiple panoramic captures and enabling looming, view-pointselective occlusion and disocclusion of background scene objects. We have integrated this client with a sibling client based on Java3d, allowing realtime visualization of the dollying, and ...

Lesions in 12 cats that destroyed almost all of area 17 (Group MS) abolished differential responding on the visual cliff. Performance was not impaired in 9 cats in which regions of the striate cortex were spared in the depths of the splenial sulcus or in 23 cats with damage to extramarginal areas. There were 37 controls. Additional experiments indicated that the deficit in performance by MS cats was not reduced either by the administration of amphetamine or by increases in cues for motion parallax. Monocularly occluded normal cats preferred the shallow surface of the visual cliff, demonstrating that the deficit was not due solely to removal of neurons sensitive to binocular disparity. The findings were discussed in light of electrophysiological evidence that lesions of the visual cortex disrupt functions of the superior colliculus. Cats appear to be less dependent upon the visual cortex for depth perception than are some other mammals. Removal of the visual cortex disrupts performance on the visual cliff in rats (Lewellyn, Lowes, & Isaacson, 1969; P. M. Meyer, Anderson, & Braun, 1966) and rabbits (Stewart & Ricsen, 1972), but the results of a program of similar experiments with cats are mixed. In three of the four studies, lesions of the visual cortex failed to alter preferences for the shallow side of the visual cliff (Dalby, Meyer, &

Background: Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. Methodology/Principal Findings: We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Redtailed Hawks have relatively small binocular areas (,33u) and wide blind areas (,82u), but intermediate degree of eye movement (,5u), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (,36u), small blind areas (,60u), and high degree of eye movement (,8u), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (,1u) may help stabilize the image when hovering above prey before an attack. Conclusions: We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while perching.

We show that the parallax motion resulting from non-nodal rotation in panorama capture can be exploited for light field construction from commodity hardware. Automated panoramic image capture typically seeks to rotate a camera exactly about its nodal point, for which no parallax motion is observed. This can be difficult or impossible to achieve due to limitations of the mounting or optical systems, and consequently a wide range of captured panoramas suffer from parallax between images. We show that by capturing such imagery over a regular grid of camera poses, then appropriately transforming the captured imagery to a common parameterisation, a light field can be constructed. The resulting four-dimensional image encodes scene geometry as well as texture, allowing an increasingly rich range of light field processing techniques to be applied. Employing an Ocular Robotics REV25 camera pointing system, we demonstrate light field capture, refocusing and low-light image enhancement.

Visual display systems using fixed screens, including Immersive Projection Technology (IPT) displays, have a merit that they can provide a stable world against the user's head motion. In spite of this merit, such display systems have not been used for "telexistence in real worlds", which requires accurate stereoscopic view of live video image. We have proposed a method to realize a lived-video-based, real-time telexistence visual system with a fixed screen: to keep the orientation of the camera constant while following the user's eye position, and to control the position and size of the video image for each eye on the screen in real time. We have also designed technical elements to compose the system, i.e., a constant-orientation camera system and real-time 2D image manipulation (shifting and resizing) subsystem. In this paper, we describe the design and implementation of the entire system that realizes fixed-screen-based telexistence, which inherently has an ability of showing a stable remote world.

The determinants of visual scale (size a d distance) under monocular viewing are still largely unknoyh. The problem of visual scale under monocular viewing becomes readily apparent when one moves about within a virtual environment. It might be thought that the absolute motion parallax of stationary objects (both in real and virtual environments), under the assumption of their stationarity, would immediately determine their apparent size and dis@ce for an observer who is walking about. We sought to assess the effectiveness of observer-produced motion parallax irl scaling apparent size and distance within near space. We had subjects judge the apparent size and distance of real and v q objects under closely matched conditions. Real and virtual targets were 4 spheres seen in darkness at eye level. The target$ ranged in diameter fiom 3.7 cm to 14.8 cm and were viewed monocularly fiom different distances, with a subset of the size/bstance combinations resulting in projectively equivalent stimuli at the viewing origin. Subjects moved laterally plus and binus 1 m to produce large amounts of motion parallax. When angular size was held constant and motion parallax acted as a differential cue to target size and distance, judged size varied by a factor of 1.67 and 1.18 for the real and virtual environments, respectively, well short of the four-fold change in distal size. Similarly, distance judgments varied by factors of only 1.74 and 1.07, respectively. We conclude that absolute motion parallax only weakly determines the visual scale of nearby objects varying over a four-fold range in size.

Equirectangular panoramas are popular tools for achieving 360 degree immersed viewing experiences. A panorama captures a scene from one point and panoramic viewers allow the user to control the viewing direction, but the viewer is not allowed to move around. This study proposes a strategy for transforming equirectangular panoramic images with the effect of moving freely in three dimensions. The strategy assumes that the panorama is an enclosed space comprising a flat ground and flat vertical walls. A equirectuangular Hough transform is proposed for detecting the boundaries of the respective planes. The panoramic image is then decomposed into the respective planes, the viewing point is translated and a new panoramic image based on the new viewing position is composed. Preliminary proof of concept test shows that the strategy allows free translation within simple panoramic images.

Previous research into the uptake of ICT by teachers in schools has shown that there is often a tension between teachers’ traditional practices and the approaches to incorporating new technologies (TEL) within a conventional course (Webb and Cox, 2004). In higher education, the adoption of TEL is often even more constrained because of the requirements to cover many degree topics, teach large student cohorts, meet strict deadlines and for university teachers to keep up with their research as well as teaching commitments. Although there have been many initiatives in HE to adopt TEL since the mid 1970s and to research its effects on the HE curriculum, (e.g. Cox and Lewis, 1978, Laurillard, 1993, Reynolds et al., 2007) there have been relatively few which have focused on the impact on the curriculum delivery itself, its impact on university teachers’ practices and how these interrelate with the technology development, the research methods and theories used. The purpose of the curriculum...