Effects of Time Delay on Depth Perception via Head-Motion Parallax in Virtual Environment Systems

2000 ◽  
Vol 9 (6) ◽  
pp. 638-647 ◽  
Author(s):  
Hanfeng Yuan ◽  
W. L. Sachtler ◽  
Nat Durlach ◽  
Barbara Shinn-Cunningham
Keyword(s):  
Time Delay ◽  
Virtual Environment ◽  
Depth Perception ◽  
Head Movement ◽  
Time Delays ◽  
Motion Parallax ◽  
Head Motion ◽  
Depth Cues ◽  
Random Dot Patterns

Experiments were conducted to determine how the ability to detect and discriminate head-motion parallax depth cues is degraded by time delays between head movement and image update. The stimuli consisted of random-dot patterns that were programmed to appear as one cycle of a sinusoi dal grating when the subject's head moved. The results show that time delay between head movement and image update has essentially no effect on the ability to discrimi nate between two such gratings with different depth char acteristics when the delay is less than or equal to roughly 265 ms.

Motion Parallax as an Independent Cue for Depth Perception

Perception ◽  
1979 ◽  
Vol 8 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Brian Rogers ◽  
Maureen Graham
Keyword(s):  
Depth Perception ◽  
Close Agreement ◽  
Motion Parallax ◽  
Three Dimensional ◽  
Matching Task ◽  
Relative Depth ◽  
Relative Movement ◽  
Random Dot Stereograms ◽  
Random Dot Patterns ◽  
Dimensional Surface

The perspective transformations of the retinal image, produced by either the movement of an observer or the movement of objects in the visual world, were found to produce a reliable, consistent, and unambiguous impression of relative depth in the absence of all other cues to depth and distance. The stimulus displays consisted of computer-generated random-dot patterns that could be transformed by each movement of the observer or the display oscilloscope to simulate the relative movement information produced by a three-dimensional surface. Using a stereoscopic matching task, the second experiment showed that the perceived depth from parallax transformations is in close agreement with the degree of relative image displacement, as well as producing a compelling impression of three-dimensionality not unlike that found with random-dot stereograms.

Localization of a Time-Delayed, Monocular Virtual Object Superimposed on a Real Environment

2000 ◽  
Vol 9 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Jeffrey W. McCandless ◽  
Stephen R. Ellis ◽  
Bernard D. Adelstein
Keyword(s):  
Time Delay ◽  
Time Delays ◽  
Motion Parallax ◽  
Virtual Object ◽  
Distance Information ◽  
Object Position ◽  
Real Environment ◽  
Judgment Error ◽  
Projected Position ◽  
Apparent Stability

Observers adjusted a pointer to match the depicted distance of a monocular virtual object viewed in a see-through, had-mounted display. Distance information was available through motion parallax produced as the observers rocked side to side. The apparent stability of the virtual object was impaired by a time delay between the observers' head motions and the corresponding change in the object position on the display. Localizations were made for four time delays (31 ms, 64 ms, 131 ms, and 197 ms) and three depicted distances (75 cm, 95 cm, and 113 cm). The errors in localizations increased systematically with time delay and depicted distance. A model of the results shows that the judgment error and lateral projected position of the virtual object are each linearly related to time delay.

scholarly journals Comparison between Lateral Head Movement and To-and-Fro Head Movement on Depth Perception from Motion Parallax

i-Perception ◽  
10.1068/ic393 ◽  
2011 ◽  
Vol 2 (4) ◽  
pp. 393-393
Author(s):  
Masahiro Ishii ◽  
Masashi Fujita ◽  
Masayuki Sato
Keyword(s):  
Depth Perception ◽  
Head Movement ◽  
Motion Parallax ◽  
Lateral Head

Two Stages for Depth Integration of Motion Parallax

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 163-163
Author(s):  
H Ujike ◽  
S Saida
Keyword(s):  
Apparent Motion ◽  
Depth Perception ◽  
Head Movement ◽  
Motion Parallax ◽  
Head Movements ◽  
Integration Time ◽  
Motion Signal ◽  
Motion Threshold ◽  
Sinusoidal Gratings ◽  
Two Stages

Motion parallax has been shown to be a principal cue for depth perception under monocular viewing. The simulated depth of stimuli in previous studies has been constant in both magnitude and direction. In the present study we addressed the question how the visual system detects parallactic depth change. To answer this we investigated the temporal characteristics of parallactic depth change and the effect of a motion signal on them. The stimulus consisted of four bands of 15-cycle sinusoidal gratings and parallactic depth was simulated between each band. In experiment 1, we measured the amount of perceived depth change with different frequencies (0.125 to 10 Hz) of simulated depth change and with different velocities (2.5 to 40 cm s−1) of head movements. The result showed the perceived depth change decreased with frequency of depth change, and it increased with head velocity when the frequency was constant. In experiment 2, we measured the motion threshold with different velocities of head movement. The result showed the threshold was constant across different head velocities. In experiment 3, we measured the amount of perceived depth using apparent motion stimuli with the head moving. The result showed depth decreased with SOA of apparent motion stimuli, but there was no effect of different head velocities. The results of these three experiments indicate that parallactic depth change is determined by the duration of simulated depth, which corresponds to the integration time of motion, as well as by the extent of head movement. We conclude that parallactic depth is integrated in two stages: first, integration of motion and, second, integration of motion parallax.

Motion Parallax Driven by Head Movements: Conditions for Visual Stability, Perceived Depth, and Perceived Concomitant Motion

Perception ◽  
10.1068/p5221 ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 477-490 ◽  
Author(s):  
Hiroshi Ono ◽  
Hiroyasu Ujike
Keyword(s):  
Motion Perception ◽  
Depth Perception ◽  
Head Movement ◽  
Motion Parallax ◽  
Head Movements ◽  
Visual Stability ◽  
Movement Velocity ◽  
Motion Threshold ◽  
Perceived Motion

Yoking the movement of the stimulus on the screen to the movement of the head, we examined visual stability and depth perception as a function of head-movement velocity and parallax. In experiment 1, for different head velocities, observers adjusted the parallax to find (a) the depth threshold and (b) the concomitant-motion threshold. Between these thresholds, depth was seen with no perceived motion. In experiment 2, for different head velocities, observers adjusted the parallax to produce the same perceived depth. A slower head movement required a greater parallax to produce the same perceived depth as faster head movements. In experiment 3, observers reported the perceived depth for different parallax magnitudes. Perceived depth covaried with smaller parallax without motion perception, but began to decrease with larger parallax and concomitant motion was seen. Only motion was seen with the larger parallax.

Depth Perception in Alzheimer's Disease

1996 ◽  
Vol 83 (3) ◽  
pp. 987-995 ◽  
Author(s):  
Mario F. Mendez ◽  
Monique M. Cherrier ◽  
Robert S. Meadows
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Depth Perception ◽  
Motion Parallax ◽  
Relative Size ◽  
Depth Cues ◽  
Visuospatial Deficits ◽  
Visuospatial Functions ◽  
Monocular Depth ◽  
Global Stereopsis

Abnormal depth perception contributes to visuospatial deficits in Alzheimer's disease. Disturbances in stereopsis, motion parallax, and the interpretation of static monocular depth cues may result from neuropathology in the visual cortex. We evaluated 15 patients with mild Alzheimer's disease and 15 controls matched for age, sex, and education on measures of local stereopsis (stereoscopic testing), global stereopsis (random dots), motion parallax (Howard-Dolman apparatus), and monocular depth perception by relative size, interposition, and perspective. Compared to controls, the patients were significantly impaired in over-all depth perception. This impairment was largely due to disturbances in local stereopsis and in the interpretation of depth from perspective, independent of other visuospatial functions. Patients with Alzheimer's disease have disturbed interpretation of monocular as well as binocular depth cues. This information could lead to optic interventions to improve their visual depth perception.

Dynamic Occlusion and Motion Parallax in Depth Perception

Perception ◽  
1988 ◽  
Vol 17 (2) ◽  
pp. 255-266 ◽  
Author(s):  
Hiroshi Ono ◽  
Brian J Rogers ◽  
Masao Ohmi ◽  
Mika E Ono
Keyword(s):  
Relative Motion ◽  
Depth Perception ◽  
Motion Parallax ◽  
Three Dimensional ◽  
Depth Order ◽  
Depth Cues ◽  
Small Depth ◽  
Stationary Observer ◽  
Depth Separation ◽  
Condition B

Random-dot techniques were used to examine the interactions between the depth cues of dynamic occlusion and motion parallax in the perception of three-dimensional (3-D) structures, in two different situations: (a) when an observer moved laterally with respect to a rigid 3-D structure, and (b) when surfaces at different distances moved with respect to a stationary observer. In condition (a), the extent of accretion/deletion (dynamic occlusion) and the amount of relative motion (motion parallax) were both linked to the motion of the observer. When the two cues specified opposite, and therefore contradictory, depth orders, the perceived order in depth of the simulated surfaces was dependent on the magnitude of the depth separation. For small depth separations, motion parallax determined the perceived order, whereas for large separations it was determined by dynamic occlusion. In condition (b), where the motion parallax cues for depth order were inherently ambiguous, depth order was determined principally by the unambiguous occlusion information.

The myth of visual depth cues V: Motion parallax

2021 ◽  
Author(s):  
Lydia Maniatis
Keyword(s):  
Depth Perception ◽  
Motion Parallax ◽  
Convincing Evidence ◽  
The Other ◽  
Visual Depth ◽  
Independent Factor ◽  
Depth Cues ◽  
Depth Cue

Motion parallax is conventionally described as a “depth cue.” Rogers & Graham (1979) are credited with providing fairly convincing evidence for this view. Here, I argue that, just as in the case of the other so-called “depth cues,” the claim that “motion parallax” constitutes an independent factor supporting shape and depth perception is circular. Authors offering apparent demonstrations of this cue fail to properly distinguish between proximal and distal stimulus and overlook the fundamental confound of figural organization.

scholarly journals Acceleration (Deceleration) Model Supporting Time Delays to Refresh Data

2018 ◽  
Vol 30 (2) ◽  
pp. 141-149 ◽  
Author(s):  
José Gerardo Carrillo González ◽  
Jesús Arámburo Lizárraga ◽  
Liliana Ibeth Barbosa Santillán
Keyword(s):  
Mathematical Model ◽  
Time Delay ◽  
Virtual Environment ◽  
Time Delays ◽  
Maximum Speed ◽  
Car Following ◽  
Traffic Intersection

This paper proposes a mathematical model to regulate the acceleration (deceleration) applied by self-driving vehicles in car-following situations. A virtual environment is designed to test the model in different circumstances: (1) the followers decelerate in time if the leader decelerates, considering a time delay of up to 5 s to refresh data (vehicles position coordinates) required by the model, (2) with the intention of optimizing space, the vehicles are grouped in platoons, where 3 s of time delay (to update data) is supported if the vehicles have a centre-to-centre spacing of 20 m and a time delay of 1 s is supported at a spacing of 6 m (considering a maximum speed of 20 m/s in both cases), and (3) an algorithm is presented to manage the vehicles’ priority at a traffic intersection, where the model regulates the vehicles’ acceleration (deceleration) and a balance in the number of vehicles passing from each side is achieved.

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