Search results for "stereopsis"
showing 10 items of 42 documents
Panel Summary One Model for Vision Systems?
1994
This panel reports some considerations about the definition of vision-models. The panellists are scientists working on vision problems from different perspectives. The concept of model in vision seems to remain still open. In fact, it is dynamic, and context dependent. There exists the need for a better exchange of information, among biologists, engineers, physicists, and psychologists in order to improve our knowledge.
Binocular Vision in Patients with Multiple Sclerosis.
2021
Amparo Gil-Casas,1,2 David P Piñero-Llorens,2 Ainhoa Molina-Martin2 1Clínica Optométrica, Fundació Lluís Alcanyís, University of Valencia, Valencia, Spain; 2Optics and Visual Perception Group (GOPV), Department of Optics, Pharmacology, and Anatomy, University of Alicante, Alicante, SpainCorrespondence: Ainhoa Molina-MartinDepartment of Optics, Pharmacology, and Anatomy, University of Alicante, Carretera San Vicente del Raspeig, San Vicente del Raspeig, 03690, Alicante, SpainTel +34 965 903-400Email ainhoa.molina@ua.esPurpose: Oculomotor disorders have been reported in multiple sclerosis (MS) in up to 80% of cases. There have …
A real-time auto calibration technique for stereo camera
2020
Calibration of the internal and external parameters of a stereo vision camera is a well-known research problem in the computer vision. Usually, to get accurate 3D results the camera should be manua...
Effects of symmetry, texture, and monocular viewing on geographical slant estimation.
2018
Hills often appear to be steeper than they are. The unusual magnitude of this error has prompted extensive experimentation. The judgment mode, such as verbal vs. action-based measures, the state of the observer - whether exhausted or well rested - all can influence perceived geographical slant. We hold that slant perception is inherently shaky as soon as the slope in question is no longer palpable, that is if it is outside our personal space. To make this point, we have added symmetry, texture, and depression to the list of factors that might modulate slant perception. When the frontal slope of a hill is to be judged, it appears steeper when the side slopes are steep. We have used model hil…
<title>Assessment of ocular stereovision prevalence and eye dominance stability</title>
2005
The paper reports on the development of the equipment for studies of the eye dominance and ocular stereoprevalence by using black-and-white and color stereostimuli. The stereostimuli are separated either by color-filter goggles or phase separating liquid-crystal-shutter goggles. The stability of the stereoprevalence is studied by artificial step-by-step deterioration of the retinal image quality, particularly in the dominant eye. The stimuli are blurred using spatial Gaussian filtering. The polymer-dispersed-liquid-crystal cell placed in front of the dominant eye induces a controllable light scattering. The stimuli-blurring and light-scattering methods exhibit different influence on the eye…
Visual performance comparison between contact lens-based pinhole and simultaneous vision contact lenses.
2011
Background The aim was to evaluate the visual performance provided with a contact lens-based pinhole design against a simultaneous vision multifocal contact lens. Methods In a cross-over study at the University of Valencia, 22 presbyopic patients were evaluated using an artificial pupil fitted on the non-dominant eye and the simultaneous vision PureVision Multifocal contact lenses. After one month of contact lens wear, binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance contrast sensitivity, binocular near contrast sensitivity, and stereoacuity were measured, under photopic conditions (85 cd/m2). In addition, binocular distance vis…
A Random Dot Stereoacuity Test based on 3D Technology
2014
This paper presents a novel stereo acuity test that is realized by a software program on a PC with 3D capabilities. The 3D technology is used to provide two separate images to the two eyes. The test is a classical random dot test, but differently to other test printed on paper, the images shown to the patient can vary and there is no monocular clue. These features allow to deliver the test also in groups (instead of individuals) like school classes, and to increase the sensitivity. The system can be easily used also by not specialized personnel and this may further increase the cost efficiency of the test. Experiments carried on with a large set of children of age between five and seven yea…
<title>Estimation of stereovision in conditions of blurring simulation</title>
2005
The aim of this study was to evaluate the simulation of eye pathologies, such as amblyopia and cataracts, to estimate the stereovision in artificial conditions, and to compare the results on the stereothreshold obtained in artificial and real- pathologic conditions. Characteristic of the above-mentioned real-life forms of a reduced vision is a blurred image in one of the eyes. The blurring was simulated by (i) defocusing, (ii) blurred stimuli on the screen, and (iii) occluding of an eye with PLZT or PDLC plates. When comparing the methods, two parameters were used: the subject's visual acuity and the modulation depth of the image. The eye occluder method appeared to systematically provide h…
Stereopsis assessment at multiple distances with an iPad application
2017
[EN] We present a new application for iPad for screening stereopsis at multiple distances that allows testing up to ten levels of stereoacuity at each distance. Our approach is based on a random dot stereogram viewable with anaglyph spectacles. Sixty-five subjects with no ocular diseases, wearing their habitual correction were measured at 3 m and 0.5 m. Results were compared with a standard stereoscopic test (TNO). We found not statistically significant differences between both tests, but our method achieved higher reproducibility. Applications in visual screening programs and to design and use of 3D displays, are suggested. (C) 2017 Elsevier B.V. All rights reserved.
ACCURATE DENSE STEREO MATCHING FOR ROAD SCENES
2017
International audience; Stereo matching task is the core of applications linked to the intelligent vehicles. In this paper, we present a new variant function of the Census Transform (CT) which is more robust against radiometric changes in real road scenes. We demonstrate that the proposed cost function outperforms the conventional cost functions using the KITTI benchmark. The cost aggregation method is also updated for taking into account the edge information. This enables to improve significantly the aggregated costs especially within homogenous regions. The Winner-Takes-All (WTA) strategy is used to compute disparity values. To further eliminate the remainder matching ambiguities , a post…