Technology Study on the Different Cognitive Process of Stereopsis between Crossed and Uncrossed Fine Disparity

2014 ◽  
Vol 886 ◽  
pp. 374-377
Author(s):  
Yan Wu ◽  
Qi Li
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Cognitive Process ◽  
Three Dimensional ◽  
Reaction Times ◽  
Visual Fatigue ◽  
Technology Study ◽  
Random Dot Stereograms ◽  
Display Technology ◽  
Made In

Considerable improvements in display technology were made in stereoscopic imaging and image quality rose with technical progress. But there was not enough effort on reducing visual fatigue. The study was to investigate one of the ways to reduce visual fatigue caused by three-dimensional images. Static random-dot stereograms (RDS) were used as stimuli. The performance of every subject was recorded with disparate disparities of 3.27', 6.54', 8.18', 11.45', 14.72', 17.99', 21.26', and 24.53'. Results showed that reaction times were always longer in the uncrossed disparities relative to the crossed disparities. For crossed disparities, human visual system was the most sensitive to the images with disparity of 6.54'. As to uncrossed disparities, human visual system was the most sensitive to the images with disparity of 8.18'.

A Study on the Cognitive Process of Stereopsis in Small Uncrossed Disparity

2014 ◽  
Vol 513-517 ◽  
pp. 3655-3658
Author(s):  
Yan Wu ◽  
Qi Li
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Cognitive Process ◽  
Reaction Times ◽  
Normal Subjects ◽  
Stereo Images ◽  
Uncrossed Disparity ◽  
Random Dot Stereograms

Static random-dot stereograms (RDS) were used as stimuli to investigate the uncrossed disparity in 15 normal subjects. The response of every subject was recorded with different disparities of 3.27 arc min, 6.54 arc min, 8.18 arc min, 11.45 arc min, 14.72 arc min, 17.99 arc min, 21.26 arc min and 24.53 arc min. The results showed that the human visual system was the most sensitive to stereo images at disparity of 8.18 arc min. Disparity of 21.26 arc min had significant differences with other small disparities in reaction times, as supported the viewpoint that it was reasonable to limit the fine disparity in 20 arc min.

Parallel Processing of Luminance Steps in the Presence of Luminance Gradients

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 62-62 ◽  
Author(s):  
A Grodon ◽  
M Fahle
Keyword(s):  
Parallel Processing ◽  
Visual System ◽  
Human Visual System ◽  
Reaction Times ◽  
Step Size ◽  
Detection Thresholds ◽  
Imaginary Circle ◽  
Staircase Procedure ◽  
Dark Background ◽  
Spatial Changes

Some features of complex visual displays are analysed effortlessly and in parallel by the human visual system, without requiring scrutiny. Examples for such features are changes of luminance, colour, orientation, and movement. We measured thresholds as well as reaction times for the detection of abrupt spatial changes in luminance in the presence of luminance gradients, in order to evaluate the ability of the system to ignore such gradients. Stimuli were presented on a 20 inch monitor under control of a Silicon Graphics workstation. Luminance was calibrated by means of a photometer (Minolta). We presented between 4 and 14 rectangles simultaneously on a homogeneous dark background. Rectangles were arranged on an incomplete, imaginary circle around the fixation point and luminance changed stepwise from one rectangle to the next. Five observers had to indicate whether all luminance steps between the rectangles were subjectively equal or whether one luminance step was larger. Detection thresholds were determined for the larger step as a function of the small steps (‘base step size’) by means of an adaptive staircase procedure. The smallest luminance steps were detected when the base step size was zero and when only few rectangles were presented. Thresholds increased slightly with the number of rectangles displayed simultaneously, and to a greater extent (by up to a factor of 2) with increasing base step size. The results of all observers improved significantly through practice, by about a factor of 2. We conclude that the visual system is unable to completely eliminate gradients of luminance and to isolate sharp transitions in luminance.

scholarly journals Surface color perception in three-dimensional scenes

2006 ◽  
Vol 23 (3-4) ◽  
pp. 311-321 ◽  
Author(s):  
HUSEYIN BOYACI ◽  
KATJA DOERSCHNER ◽  
JACQUELINE L. SNYDER ◽  
LAURENCE T. MALONEY
Keyword(s):  
Visual System ◽  
Recent Work ◽  
Human Visual System ◽  
Light Field ◽  
Three Dimensional ◽  
Color Perception ◽  
Line Of Sight ◽  
Surface Color ◽  
Matte Surface ◽  
Surface Lightness

Researchers studying surface color perception have typically used stimuli that consist of a small number of matte patches (real or simulated) embedded in a plane perpendicular to the line of sight (a “Mondrian,” Land & McCann, 1971). Reliable estimation of the color of a matte surface is a difficult if not impossible computational problem in such limited scenes (Maloney, 1999). In more realistic, three-dimensional scenes the difficulty of the problem increases, in part, because the effective illumination incident on the surface (the light field) now depends on surface orientation and location. We review recent work in multiple laboratories that examines (1) the degree to which the human visual system discounts the light field in judging matte surface lightness and color and (2) what illuminant cues the visual system uses in estimating the flow of light in a scene.

An Upward-Facing Surface Appears Darker: The Role Played by the Light-From-Above Assumption in Lightness Perception

Perception ◽  
2019 ◽  
Vol 48 (6) ◽  
pp. 500-514
Author(s):  
Yuki Kobayashi ◽  
Kazunori Morikawa
Keyword(s):  
Light Intensity ◽  
Visual System ◽  
Human Visual System ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Surface Reflectance ◽  
Two Dimensional ◽  
Illusory Effect ◽  
Lightness Perception ◽  
Extract Information

The human visual system can extract information on surface reflectance (lightness) from light intensity; this, however, confounds information on reflectance and illumination. We hypothesized that the visual system, to solve this lightness problem, utilizes the internally held prior assumption that illumination falls from above. Experiment 1 showed that an upward-facing surface is perceived to be darker than a downward-facing surface, proving our hypothesis. Experiment 2 showed the same results in the absence of explicit illumination cues. The effect of the light-from-left prior assumption was not observed in Experiment 3. The upward- and downward-facing surface stimuli in Experiments 1 and 2 showed no difference in a two-dimensional configuration or three-dimensional structure, and the participants’ perceived lightness appeared to be affected by the observers’ prior assumption that illumination is always from above. Other studies have not accounted for this illusory effect, and this study’s finding provides additional insights into the study of lightness perception.

Surface Interpolation in Three-Dimensional Structure-from-Motion Perception

1989 ◽  
Vol 1 (3) ◽  
pp. 324-333 ◽  
Author(s):  
Masud Husain ◽  
Stefan Treue ◽  
Richard A. Andersen
Keyword(s):  
Visual System ◽  
Structure From Motion ◽  
Human Visual System ◽  
Human Performance ◽  
Three Dimensional ◽  
Visual Image ◽  
Dimensional Structure ◽  
Neural Network Models ◽  
Position Information ◽  
Surface Interpolation

Although it is appreciated that humans can use a number of visual cues to perceive the three-dimensional (3-D) shape of an object, for example, luminance, orientation, binocular disparity, and motion, the exact mechanisms employed are not known (De Yoe and Van Essen 1988). An important approach to understanding the computations performed by the visual system is to develop algorithms (Marr 1982) or neural network models (Lehky and Sejnowski 1988; Siegel 1987) that are capable of computing shape from specific cues in the visual image. In this study we investigated the ability of observers to see the 3-D shape of an object using motion cues, so called structure-from-motion (SFM). We measured human performance in a two-alternative forced choice task using novel dynamic random-dot stimuli with limited point lifetimes. We show that the human visual system integrates motion information spatially and temporally (across several point lifetimes) as part of the process for computing SFM. We conclude that SFM algorithms must include surface interpolation to account for human performance. Our experiments also provide evidence that local velocity information, and not position information derived from discrete views of the image (as proposed by some algorithms), is used to solve the SFM problem by the human visual system.

Are new vision standards and tests needed for military aircrew using 3D stereo helmet-mounted displays?

2020 ◽  
pp. bmjmilitary-2020-001493
Author(s):  
Bonnie Noeleen Posselt ◽  
M Winterbottom
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Three Dimensional ◽  
Testing Methods ◽  
Flight Data ◽  
Visual Systems ◽  
Overall Performance ◽  
New Vision ◽  
Medical Vision ◽  
Stereo Acuity

Visual standards for military aviators were historically set in the 1920s with requirements based on the visual systems of aircraft at the time, and these standards have changed very little despite significant advances in aircraft technology. Helmet-mounted displays (HMDs) today enable pilots to keep their head out of the cockpit while flying and can be monocular, biocular or binocular in design. With next generation binocular HMDs, flight data can be displayed in three-dimensional stereo to declutter information presented, improving search times and potentially improve overall performance further. However, these new visually demanding technologies place previously unconsidered stresses on the human visual system. As such, new medical vision standards may be required for military aircrew along with improved testing methods to accurately characterise stereo acuity.

Three-dimensional terrain model multiview quality assessment considering human visual system

2015 ◽  
Vol 9 (1) ◽  
pp. 097290
Author(s):  
Fan Zhang ◽  
Xiaoyang Li ◽  
Huan Liu ◽  
Wei Li ◽  
Wei Hu ◽  
...  
Keyword(s):  
Visual System ◽  
Quality Assessment ◽  
Human Visual System ◽  
Three Dimensional ◽  
Terrain Model

Some Notes for Anaglyph Stereo Method in the Presentation of Moving Objects

1997 ◽  
Vol 9 (2) ◽  
pp. 132-134
Author(s):  
Hitomi Koike ◽  
◽  
Masanori Idesawa ◽  
Keyword(s):  
Computer Graphics ◽  
Visual System ◽  
Human Visual System ◽  
Moving Objects ◽  
Motion Parallax ◽  
Present Report ◽  
Three Dimensional ◽  
Texture Gradient ◽  
Binocular Stereo ◽  
Three Dimensional Presentation

The human visual system perceives three-dimensional structures by using all kinds of means, such as perspective, binocular parallax, motion parallax, texture gradient, etc[2]. Among these, binocular stereo viewing based on binocular parallax is one of the most important means in perceiving the three-dimensional structures of objects. In recent years, in the field of computer graphics, the three-dimensional presentation method based on binocular stereo viewing is widely used. In research on the elucidation of the human visual mechanism, studies with the use of three--dimensional presentation methods based on binocular stereo viewing as applied to computer graphics are being , carried out actively. These studies have led to new discoveries which were never anticipated in the past, and to new knowledge concerning the human visual system. For three-dimensional presentation based on binocular viewing, various methods are used; the anaglyph method is one of them (Fig.1). According to the anaglyph method, the images of the left eye and the right eye are depicted in different colors and are observed after they are separated by means of filters corresponding to these colors. For this reason, the anaglyph method is an extremely effective one for conducting a simple experiment on binocular stereo viewing[1]. However, in the observation of moving objects which the present authors have recently conducted, a strange phenomenon was observed that a triangle rotating on a plane with a uniform depth is perceived as if it were moving in a slanted way. When this phenomenon was examined, it was confirmed that it was due to the Pulfrich effect based on the difference in brightness between red and blue colors[4]. This fact indicates that it is necessary to pay sufficient attention to the existence of this phenomenon as long as the anaglyph method is used for the presentation and observation of moving objects. The present report is intended to introduce several of phenomena observed in the course of the study on the cause of this phenomenon.

Sign in / Sign up

Export Citation Format

Share Document