Simultaneous and Successive Contrast Effects in the Perception of Depth from Motion-Parallax and Stereoscopic Information

Perception ◽  
1982 ◽  
Vol 11 (3) ◽  
pp. 247-262 ◽  
Author(s):  
Maureen Graham ◽  
Brian Rogers
Keyword(s):  
Contrast Effect ◽  
Binocular Disparity ◽  
Motion Parallax ◽  
Three Dimensional ◽  
Vertical Surface ◽  
Test Surface ◽  
Depth Information ◽  
Apparent Depth ◽  
Contrast Effects ◽  
Inducing Surface

Prolonged inspection of a three-dimensional corrugated surface resulted in a successive contrast effect, or aftereffect, of depth, whereby a subsequently-viewed physically-flat test surface appeared to be corrugated in depth with the opposite phase to the adapting surface. The aftereffect occurred both when the depth was specified by motion parallax, in the absence of all other sources of depth information, and when it was specified solely by stereoscopic information. The depth aftereffect was measured by ‘nulling’ the apparent depth in the test surface with physical relative motion or binocular disparity until the test surface appeared flat. Up to 70% of the depth in the adapting surface was necessary to null the aftereffect. Simultaneous contrast effects in the perception of three-dimensional surfaces were used to investigate the spatial interactions that exist in the processing of motion-parallax and stereoscopic information. A physically vertical surface appeared to slope in depth in the opposite direction to the slope of a surrounding surface. In this case up to 50% of the slope of the inducing surface was necessary to null the contrast effect. Similar results were again obtained for motion-parallax and stereoscopic depth.

Interaction between Colour and Depth Channels in Transparent Colour Perception

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 115-115
Author(s):  
K Okajima ◽  
M Takase ◽  
S Takahashi
Keyword(s):  
Information Processing ◽  
Visual System ◽  
Binocular Disparity ◽  
Depth Information ◽  
Apparent Depth ◽  
Colour Perception

Two colours can be perceived at one location on overlapping planes only when the front plane is transparent. This phenomenon suggests that colour information processing is not independent of depth information processing and vice versa. To investigate the interaction between colour and depth channels, we used colour stimuli and binocular parallax to identify the conditions for transparency. Each stimulus, presented on a CRT to one eye, consisted of a centre patch and a surround. Binocular disparity was set so that the centre patch could be seen behind the surround. However, the surround appears to be behind the centre patch when the surround is perceived as an opaque plane. We examined several combinations of basic colours for the centre patch and surround. The surround luminance was constant at 1.0 cd m−2 and the luminance of the centre was varied. Subjects used the apparent depth of the surround to report whether or not transparency occurred. The results show two types of transparency: ‘bright-centre transparency’ and ‘dark-centre transparency’. We found that the range of centre luminances which yield transparency depends on the combination of centre and surround colours, ie influences of brightness and colour opponency were found. We conclude that there is interaction between colour and depth channels in the visual system.

The Appearance of Surfaces Specified by Motion Parallax and Binocular Disparity

1989 ◽  
Vol 41 (4) ◽  
pp. 697-717 ◽  
Author(s):  
Brian J. Rogers ◽  
Thomas S. Collett
Keyword(s):  
Visual System ◽  
Binocular Disparity ◽  
Motion Parallax ◽  
Vertical Axis ◽  
Line Of Sight ◽  
Depth Information ◽  
Real Surface ◽  
Corrugated Surface ◽  
Corrugated Surfaces ◽  
Matching Technique

The experiments reported in this paper were designed to investigate how depth information from binocular disparity and motion parallax cues is integrated in the human visual system. Observers viewed simulated 3-D corrugated surfaces that translated to and fro across their line of sight. The depth of the corrugations was specified by either motion parallax, or binocular disparities, or some combination of the two. The amount of perceived depth in the corrugations was measured using a matching technique. A monocularly viewed surface specified by parallax alone was seen as a rigid, corrugated surface translating along a fronto-parallel path. The perceived depth of the corrugations increased monotonically with the amount of parallax motion, just as if observers were viewing an equivalent real surface that produced the same parallax transformation. With binocular viewing and zero disparities between the images seen by the two eyes, the perceived depth was only about half of that predicted by the monocular cue. In addition, this binocularly viewed surface appeared to rotate about a vertical axis as it translated to and fro. With other combinations of motion parallax and binocular disparity, parallax only affected the perceived depth when the disparity gradients of the corrugations were shallow. The discrepancy between the parallax and disparity signals was typically resolved by an apparent rotation of the surface as it translated to and fro. The results are consistent with the idea that the visual system attempts to minimize the discrepancies between (1) the depth signalled by disparity and that required by a particular interpretation of the parallax transformation and (2) the amount of rotation required by that interpretation and the amount of rotation signalled by other cues in the display.

Optimization of Trenched Film Cooling Using RSM Coupled CFD

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
V.G. Krishna Anand ◽  
K.M. Parammasivam
Keyword(s):  
Film Cooling ◽  
Three Dimensional ◽  
Response Surfaces ◽  
Test Surface ◽  
Response Factor ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Flow Parameters ◽  
Considerable Impact ◽  
The Impact

AbstractThe trench film cooling employs film holes embedded in a slot created on the surface that requires protection from the impact of hot mainstream flow. The present investigation employs Response Surface Methodology (RSM) approach coupled with CFD analysis to develop a regression predictive model and to optimize the trench geometric and flow parameters viz., trench width (w), trench depth (d), film hole compound angle (β) and blowing ratio (M). The Area-averaged film cooling effectiveness (ȠAA) were chosen as a response factor for RSM and with trench design and flow parameters used as input factors for regression analysis. Analysis of variance (ANOVA) analysis was carried out on the regression model to identify the influence of individual parameters. Three dimensional response surfaces that relate the effect of input parameters on the response factor were analyzed. Experimental results of a case identified from the RSM matrix was found to correlate well with computational investigations. Results from the study indicate that the parameters d, β and M have considerable impact on film cooling performance of test surface with trenches.

scholarly journals Cuttlefish use stereopsis to strike at prey

2020 ◽  
Vol 6 (2) ◽  
pp. eaay6036 ◽  
Author(s):  
R. C. Feord ◽  
M. E. Sumner ◽  
S. Pusdekar ◽  
L. Kalra ◽  
P. T. Gonzalez-Bellido ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Information ◽  
Convergent Evolution ◽  
Visual Fields ◽  
Three Dimensional ◽  
Visual Information Processing ◽  
Depth Information ◽  
Cephalopod Species ◽  
Left And Right

The camera-type eyes of vertebrates and cephalopods exhibit remarkable convergence, but it is currently unknown whether the mechanisms for visual information processing in these brains, which exhibit wildly disparate architecture, are also shared. To investigate stereopsis in a cephalopod species, we affixed “anaglyph” glasses to cuttlefish and used a three-dimensional perception paradigm. We show that (i) cuttlefish have also evolved stereopsis (i.e., the ability to extract depth information from the disparity between left and right visual fields); (ii) when stereopsis information is intact, the time and distance covered before striking at a target are shorter; (iii) stereopsis in cuttlefish works differently to vertebrates, as cuttlefish can extract stereopsis cues from anticorrelated stimuli. These findings demonstrate that although there is convergent evolution in depth computation, cuttlefish stereopsis is likely afforded by a different algorithm than in humans, and not just a different implementation.

Neuronal responses to static texture patterns in area V1 of the alert macaque monkey

1992 ◽  
Vol 67 (4) ◽  
pp. 961-980 ◽  
Author(s):  
J. J. Knierim ◽  
D. C. van Essen
Keyword(s):  
Contrast Effect ◽  
Macaque Monkey ◽  
Average Difference ◽  
Contrast Effects ◽  
Neuronal Responses ◽  
Suppression Effect ◽  
Orientation Contrast ◽  
Classical Receptive Field ◽  
Oriented Line

1. We recorded responses from neurons in area V1 of the alert macaque monkey to textured patterns modeled after stimuli used in psychophysical experiments of pop-out. Neuronal responses to a single oriented line segment placed within a cell's classical receptive field (CRF) were compared with responses in which the center element was surrounded by rings of elements placed entirely outside the CRF. The orientations of the surround elements either matched the center element, were orthogonal to it, or were random. 2. The addition of the textured surround tended to suppress the response to the center element by an average of 34%. Overall, almost 80% of the 122 cells analyzed in detail were significantly suppressed by at least one of the texture surrounds. 3. Cells tended to respond more strongly to a stimulus in which there was a contrast in orientation between the center and surround than to a stimulus lacking such contrast. The average difference was 9% of the response to the optimally oriented center element alone. For the 32% of the cells showing a statistically significant orientation contrast effect, the average difference was 28%. 4. Both the general suppression and orientation contrast effects originated from surround regions at the ends of the center bar as well as regions along the sides of the center bar. 5. The amount of suppression induced by the texture surround decreased as the density of the texture elements decreased. 6. Both the general suppression and the orientation contrast effects appeared early in the population response to the stimuli. The general suppression effect took approximately 7 ms to develop, whereas the orientation contrast effect took 18-20 ms to develop. 7. These results are consistent with a possible functional role of V1 cells in the mediation of perceptual pop-out and in the segregation of texture borders. Possible anatomic substrates of the effects are discussed.

Measurement on Reaction Time of Visual Attention in Depth during Driving

2013 ◽  
Vol 319 ◽  
pp. 343-347
Author(s):  
Ru Ting Xia ◽  
Xiao Yan Zhou
Keyword(s):  
Reaction Time ◽  
Visual Attention ◽  
Measurement System ◽  
Low Vision ◽  
Three Dimensional ◽  
Depth Information ◽  
Attention Shifting ◽  
3D Space ◽  
Traffic Environment ◽  
3D Attention

This research aimed to reveal characteristics of visual attention of low-vision drivers. Near and far stimuli were used by means of a three-dimensional (3D) attention measurement system that simulated traffic environment. We measured the reaction time of subjects while attention shifted in three kinds of imitational peripheral environment illuminance (daylight, twilight and dawn conditions). Subjects were required to judge whether the target presented nearer than fixation point or further than it. The results showed that the peripheral environment illuminance had evident influence on the reaction time of drivers, the reaction time was slow in dawn and twilight conditions than in daylight condition, distribution of attention had the advantage in nearer space than farther space, that is, and the shifts of attention in 3D space had an anisotropy characteristic in depth. The results suggested that (1) visual attention might be operated with both precueing paradigm and stimulus controls included the depth information, (2) an anisotropy characteristic of attention shifting depend on the attention moved distance, and it showed remarkably in dawn condition than in daylight and twilight conditions.

scholarly journals Projection Screen with Wide-FOV and Motion Parallax Display for Teleoperation of Construction Machinery

2021 ◽  
Vol 33 (3) ◽  
pp. 604-609
Author(s):  
Daisuke Kondo ◽  
Keyword(s):  
Motion Parallax ◽  
Field Of View ◽  
Depth Information ◽  
Wide Field ◽  
Viewing Angle ◽  
Cooperative Research ◽  
Construction Machinery ◽  
Cooperative Research Center ◽  
Projection Screen ◽  
Wide Field Of View

The teleoperation of construction machinery has been introduced to mines and disaster sites. However, the work efficiency of teleoperations is lower than that of onboard operations owing to limitations in the viewing angle and insufficient depth information. To solve these problems and realize effective teleoperations, the Komatsu MIRAI Construction Equipment Cooperative Research Center is developing the next-generation teleoperation cockpit. In this study, we develop a display for teleoperations with a wide field-of-view, a portable projection screen, and a system that reproduces motion parallax, which is suitable for depth perception in the operating range of construction machinery.

Sign in / Sign up

Export Citation Format

Share Document