Search PubMed⌕ Search

PubMed · 11248263

Texture space.

Abstract

Many previous studies have examined the ease with which two spatially adjacent textures can be segmented. Our goal is to examine the representational system that determines the appearance of isolated patches of visual texture. To this end, similarity judgments from three subjects were obtained for 20 artificial textures comprising filtered noise. Multidimensional scaling (MDS) revealed that three perceptual dimensions explain most of the variance in subjects' similarity judgments. In addition, the three subjects' similarity judgments and MDS solutions were highly correlated. A computational model utilizing the energy responses in seven bandpass filters explains an average of 80% of the variability in the original similarity scores of individual subjects. In the model, energy responses are mapped to the perceptual space through a linear transformation that can be decomposed into two components. The first component decorrelates initial filter responses and the second component maps the decorrelated filter responses to a perceptual space. These latter transformations show remarkable agreement between the three subjects.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Gurnsey, D J Fleet. 2001. Texture space.. https://doi.org/10.1016/s0042-6989(00)00307-2

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Self-motion and the perception of stationary objects.

One of the ways that we perceive shape is through seeing motion. Visual motion may be actively generated (for example, in locomotion), or passively observed. In the study of the perception of three-dimensional structure from motion, the non-moving, passive observer in an environment of moving rigid objects has been used as a substitute for an active observer moving in an environment of stationary objects; this 'rigidity hypothesis' has played a central role in computational and experimental studies of structure from motion. Here we show that this is not an adequate substitution because active and passive observers can perceive three-dimensional structure differently, despite experiencing the same visual stimulus: active observers' perception of three-dimensional structure depends on extraretinal information about their own movements. The visual system thus treats objects that are stationary (in an allocentric, earth-fixed reference frame) differently from objects that are merely rigid. These results show that action makes an important contribution to depth perception, and argue for a revision of the rigidity hypothesis to incorporate the special case of stationary objects.

Form Perception↗

Role of motion integration in contour perception.

Contours are believed to play a key role in the visual analysis of scenes by the primate brain. In dynamic scenes, the presence of contours is often signaled by discontinuities in motion fields. However, it is unclear whether the motion fields over which the visual system extracts discontinuities, correspond to the local optic-flow or the pattern motion fields obtained by integrating local estimates. A resolution of this issue would provide important clues about the organization of visual motion and form analysis processes. In this paper, we present experimental evidence which suggests that the perception of motion defined contours is strongly dependent on motion integration - an operation that is believed to take place relatively late in the visual stream.

Form Perception↗

Information limitations in perception of shape from texture.

Li and Zaidi (Li, A., and Zaidi, Q. (2000) Vision Research, 40, 217-242) showed that the veridical perception of the 3-dimensional (3D) shape of a corrugated surface from texture cues is entirely dependent on the visibility of critical patterns of oriented energy. These patterns are created by perspective projection of surface markings oriented along lines of maximum 3D curvature. In images missing these orientation modulations, observers confused concavities with convexities, and leftward slants with rightward slants. In this paper, it is shown that these results were a direct consequence of the physical information conveyed by different oriented components of the texture pattern. For texture patterns consisting of single gratings of arbitrary spatial frequency and orientation, equations are derived from perspective geometry that describe the local spatial frequency and orientation for any slant at any height above and below eye level. The analysis shows that only gratings oriented within a few degrees of the axis of maximum curvature exhibit distinct patterns of orientation modulations for convex, concave, and leftward and rightward slanted portions of a corrugated surface. All other gratings exhibit patterns of frequency and orientation modulations that are distinct for curvatures on the one hand and slants on the other, but that are nearly identical for curvatures of different sign, and nearly identical for slants of different direction. The perceived shape of surfaces was measured in a 5AFC paradigm (concave, convex, leftward slant, rightward slant, and flat-frontoparallel). Observers perceived all five shapes correctly only for gratings oriented within a few degrees of the axis of maximum curvature. For all other oriented gratings, observers could distinguish curvatures from slants, but could not distinguish signs of curvature or directions of slant. These results demonstrate that human observers utilize the shape information provided by texture components along both critical and non-critical orientations.

Form Perception↗