Perception Of Relative Distance Research Articles

Effects of saturation and contrast polarity on the figure-ground organization of color on gray.

Poorly saturated colors are closer to a pure gray than strongly saturated ones and, therefore, appear less “colorful.”Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role of color saturation in such figure-ground organization has remained unclear. We presented configurations of colored inducers on gray “test” backgrounds to human observers. Luminance and saturation of the inducers was uniform on each trial, but varied across trials. We ran two separate experimental tasks. In the relative background brightness task, perceptual judgments indicated whether the apparent brightness of the gray test background contrasted with, assimilated to, or appeared equal (no effect) to that of a comparison background with the same luminance contrast. Contrast polarity and its interaction with color saturation affected response proportions for contrast, assimilation and no effect. In the figure-ground task, perceptual judgments indicated whether the inducers appeared to lie in front of, behind, or in the same depth with the background. Strongly saturated inducers produced significantly larger proportions of foreground effects indicating that these inducers stand out as figure against the background. Weakly saturated inducers produced significantly larger proportions of background effects, indicating that these inducers are perceived as lying behind the backgrounds. We infer that color saturation modulates figure-ground organization, both directly by determining relative inducer depth, and indirectly, and in interaction with contrast polarity, by affecting apparent background brightness. The results point toward a hitherto undocumented functional role of color saturation in the genesis of form, and in particular figure-ground percepts in the absence of chromatostereopsis.

The ground is dominant in infants’ perception of relative distance

When making relative distance judgments, adults attend to information provided by the ground surface and generally ignore information provided by ceiling surfaces. In the present study, we asked whether this ground dominance effect is present in infancy. Groups of 5- and 7-month-old infants viewed a display depicting textured ground and ceiling surfaces. Two toys, which were attached to vertical rods, were affixed to the display. The toys/rods were positioned so that one toy was specified as being nearer by the ground surface but farther away by the ceiling surface, while the other toy was specified as being farther away by the ground surface but nearer by the ceiling surface. Under monocular viewing conditions, the infants in both age groups reached preferentially for the toy that was specified as being nearer by the ground surface. This effect was significantly stronger than that observed under binocular viewing conditions. The findings indicate that the infants responded to the distance information provided by the ground surface to a greater extent than to information provided by the ceiling.

The perception of relative distance depends on the size-ratio in photographs 2

The perception of relative distance depends on the size-ratio in photographs 2

The perception of relative distance depends on the size-ratio in photographs

The perception of relative distance depends on the size-ratio in photographs

Effects of texture gradients and the horizon-ratio relation on the perception of relative distance

Effects of texture gradients and the horizon-ratio relation on the perception of relative distance

Role of a Texture Gradient in the Perception of Relative Size

Two theories regarding the role of a texture gradient in the perception of the relative size of objects are compared. Relational theory states that relative size is directly specified by the projective ratio of the numbers of texture elements spanned by objects. Distance calibration theory assumes that relative size is a product of visual angle and distance, once the distance is specified by the texture. Experiment 1 involved three variables: background (no texture, texture gradient patterns), the ratio of heights of the comparison stimulus to a standard (three levels), and angular vertical separation of the standard stimulus below the horizon (two levels). The effect of the retinal length of the comparison stimulus was examined in experiment 2. In both experiments, participants judged both the apparent size and distance of a comparison stimulus relative to a standard stimulus. Results suggest that the cues selected by observers to judge relative size were to some degree different from those used to judge relative distance. Relative size was strongly affected by a texture gradient and the retinal length of a comparison stimulus whereas relative distance perception was affected by relative height. When dominant cues that specify size are different from those which specify distance, relational theory might provide a better account of relative size perception than distance calibration theory.

The ground dominance effect in the perception of relative distance in 3-D scenes is mainly due to characteristics of the ground surface

Previously, we (Bian, Braunstein, and& Andersen, 2005) reported a dominance effect of the ground plane over other environmental surfaces in determining the perceived relative distance of objects in 3-D scenes. In the present study, we conducted three experiments to investigate whether this ground dominance is due to inherent differences between ground and ceiling surfaces, or to the locations of these surfaces in the visual field. In Experiment 1, two vertical posts were positioned between a ground surface and a ceiling surface, and optical contact was manipulated so that the two surfaces provided contradictory information about the relative distances of the posts from the participant. The two surfaces were either both above, both below, or one above and one below fixation. In Experiment 2, only one surface was presented, either above, below, or at fixation. In Experiment 3, the posts were replaced by two red dots, and the eccentricity of the optical contact on the two surfaces was equated in each of five locations in the visual field. In all three experiments, participants judged which of the two objects appeared to be closer. Overall, we found a higher proportion of judgments consistent with a ground surface than with a ceiling surface in all locations, indicating that the ground dominance effect is mainly due to characteristics of the ground surface, with location in the visual field having only a minor effect.

Perception of relative distance in a driving simulator1,2

Abstract: The aim of this experiment was to test, in a driving simulator, how a subject can control his approach towards several simulated car‐targets in different driving contexts. We assume that increasing complexity might influence driving performance according to the difficulty of perceiving distances properly. The subjects’ first task consisted of placing their car at an equal distance between two preceding cars. In the second task, the subjects had to place their car level with the preceding car. The target cars were either static or running at 40 or 60 km/h. The results showed a more precise distance perception when the difficulty of the task decreased. In all conditions the subjects underestimated distances. Subjects were better at 60 km/h than at 40 km/h and the performance improved with smaller car distances. In conclusion, the alignment tasks produced better performances than the mid‐distance tasks, as a consequence of their lower complexity. However, physical constraints due to the increase in velocity, as well as shorter distances between vehicles, improved performances.

Relative distance perception by manipulating the ILD of HRTFs

Relative distance perception by manipulating the ILD of HRTFs

On the difference between absolute and relative auditory distance perception

Absolute distance perception in the absence of information about intensity and reflections from boundaries is quite difficult [B. G. Haustein, Hochfrequenztech. u. Elektroakustik 78, 46–57 (1969)] but is possible to achieve if a sound source exists within the distance of around 1 to 2 m from a listener. In the presence of multiple sound sources, however, some cues can be derived by comparing information from different sources. From this point of view, it is important to study relative distance perception between sounds from multiple sources to investigate general distance perception in auditory system. Thus using the same experimental setup, two kinds of listening experiments about the absolute and relative distance perception were conducted. In the experiment for relative distance perception, a subject was asked to report the perceived distances of two sound sources presented successively with an interval of 2 s by using a rating scale with seven categories. The results of absolute distance perception showed that the perceived distance of a sound image significantly increases with the increase of actual distance of the sound source up to around 1.2 m. On the other hand, the results of the relative auditory distance perception showed that the perceived distance significantly increases up to 2 to 3 m.

Auditory perception of relative distance of traffic sounds

This study examines the accuracy of judgements of relative distance of traffic sounds (car and lorry) compared with nonattributed sounds (white noise). Adults judged whether sounds were comparatively nearer or further away in both conditions when decibel levels were the same and when decibel levels differed. Results indicated that judgement of relative distance is generally difficult and that such judgements are not based on loudness alone, particularly for traffic sounds. More errors were made when decibel levels were the same, indicating a reluctance to rely on loudness as an indicator of distance. Also more errors were made for traffic sounds. It was suggested that nonauditory criteria may be used in interpreting sounds, possibly including past experience and visual imagery. Finally, the implications of the results for road safety are discussed.

Relative Distance Perception Through Expanding and Contracting Motion and the Role of Propiospecific Information in Walking

Two experiments using a new device that correlates simulated optic flow with forward and backward head motions are reported. The first experiment tested the effectiveness of the rate of optical expansion/contraction as a cue for relative distance perception; the second experiment examined the role of propriospecific information in determining whether or not a simulated wall was perceived to moving relative to the ground. In walking along the line of sight in a stationary environment, the image of a nearer object expands/contracts more than the image of objects farther away. In Experiment 1, observers' abilities to judge which of two walls was nearer, according to expanding/contracting patterns, were tested. The results show that both walking and stationary observers can detect the order of depth from expansion patterns but not from the contraction patterns. Experiment 2 assessed the role of propriospecific information for specifying the motion or nonmotion of simulated 'wall' relative to the ground. The r...

A note on "Optical motions as information for unsigned depth".

Farber and McConkie have questioned whether optical (or retinal) flows provide a basis for the accurate perception of relative distance (or filled depth, in Gibson, Gibson, Smith, & Flock's terms). Some of the analysis Farber and McConkie present is incorrect. In this article I identity some of the fallacies and discuss issues relevant to these fallacies. The critique does not concern the experiments presented by Farber and McConkie but rather the underlying analysis that culminated in the experiments.

Texture of the stimulus field and age as variables in the perception of relative distance in photographic slides

The perception of relative distance in the third dimension, on the basis of photographic stimulus fields, was studied in children in Grades 1, 4, 8, and 9, and college adults. Photographic slides were made of stimulus fields constructed to represent four degrees of texture density and four degrees of regularity of patterning of the texture elements. For each texture the perceived midpoint of a standard distance was determined by means of an adaptation of the method of constant stimuli. The results indicated a general error of underestimation (underconstancy), which decreased some-what with age. At all age levels this error decreased as texture density increased, but there was no significant interaction between age and texture. Regularity of patterning produced less consistent effects, though there was an over-all increase in constancy from the least to the most regular pattern. The judgments showed a high degree of consistency at all age levels, pointing to the advantages of this type of psychophysical method for the study of perceptual judgments in children.

Interposition as a Cue for the Perception of Relative Distance

Interposition as a Cue for the Perception of Relative Distance