Why do some colors look special? Color vision is our ability to distinguish the spectral characteristics of light. Wavelength varies continuously, yet we perceive spectra in terms of a small number of dimensions anchored by salient landmarks. These dimensions define a color space, within which colors appear to vary in hue (direction) or saturation (distance) relative to a neutral gray (Figure 1...

Usually, a fabric weave pattern is recognized using methods which identify the warp floats and weft floats. Although these methods perform well for uniform or repetitive weave patterns, in the case of complex weave patterns, these methods become computationally complex and the classification error rates are comparatively higher. Furthermore, the fault-tolerance (invariance) and stability (selec...

We used a recognition memory paradigm to assess the visual memory of X-chromosome-linked dichromats for color images of natural scenes. The performance of 17 protanopes and 14 deuteranopes, who lack the second (red-green opponent) subsystem of color vision, but retain the primordial (yellow-blue opponent) subsystem, was compared with that of 36 color normal observers. During the presentation ph...

A retinally stabilized object readily undergoes perceptual fading. It is commonly believed that the color of the apparently vanished object is Wlled in with the color of the background because the features of the Wlled-in area are determined by features located outside the stabilized boundary. Crane, H. D., & Piantanida, T. P. (1983) (On seeing reddish green and yellowish blue. Science, 221, 10...

Many aspects of visual coding have been successfully predicted by starting from the statistics of natural scenes and then asking how the stimulus could be efficiently represented. We started from the representation of color characterized by uniform color spaces, and then asked what type of color environment they implied. These spaces are designed to represent equal perceptual differences in col...

Color images acquired through single chip digital cameras using a color filter array (CFA) contain a mixture of luminance and opponent chromatic information that share their representation in the spatial Fourier spectrum. This mixture could result in aliasing if the bandwidths of these signals are too wide and their spectra overlap. In such a case, reconstructing three-color per pixel images wi...

Observers performed red–green and yellow–blue hue cancellation tasks for a 0.8-deg circular test field on a dark surround, by manipulating the excitation level of one cone class while the other two classes were held constant. The results of the red–green judgments conformed to classical opponent color theory in that both Land S-cone excitation levels were antagonistic to M-cone signals. The yel...

In the human color vision, it is well admitted that signals issued from the three types of receptors (L, M, S) are combined in two opponent color components and one achromatic component. In this paper, we are concerned by the cardinal directions A, Cr1 and Cr2 defined by Krauskopf. We study in particular the interactions between luminance and chromatic components. These interactions should be t...