We present an optimization technique to find hue constant RGB sensors. The hue representation is based on a log RGB opponent color space that is invariant to brightness and gamma. While modeling the visual response did not derive the opponent space, the hue definition is similar to the ones found in CIE Lab and IPT. Finding hue constant RGB sensors through this optimization might be applicable ...

We have described a number of transformations by mapping the cone signal vector , formed to opponent space achromatic red-green and yellow-blue . Two new transformations, are proposed, based on CIE 2006 spectral luminous efficiency function, Hurvich's responses, without with constraints, respectively. is better than in terms best fit both improved previously proposed ones. Finally, we discuss n...

We have measured how color appearance of square-wave bars varies with stimulus strength and spatial frequency. Observers adjusted the color of a uniform patch to match the color appearance of the bars in square-wave patterns. We used low-to-moderate square-wave patterns, from 1 to 8 cycles per degree (c/deg). The matches are not photoreceptor matches but rather are established at more central n...

Modern image compression codecs produce embedded bitstreams with optimal rate-distortion properties. For natural imagery the distortion measure should by extended by a model of human color vision. The choice of the color space becomes here crucial since it has to be optimal in terms of compressibility and in terms of its visual distortion prediction properties. For three alternative color space...

According to Hering's color theory, certain hues (red vs green and blue vs yellow) are mutually exclusive as components of a single color; consequently a color cannot be perceived as reddish-green or bluish-yellow. The goal of our study is to test this key postulate of the opponent color theory. Using the method of adjustment, our observers determine the boundaries of chromatic zones in a red-g...

Color histogram is widely used in image retrieval due to its simplicity and fast operation speed. Since color histogram describes only global color distribution in an image, it is not robust to large changes in appearance and shape caused by viewing position, camera zoom, etc. To overcome this problem, we propose the method using the color edge information. Although changes in appearance and sh...

Various aspects of color have been extensively studied in science and the arts for the simple reason that it conveys information and attracts attention. In perception, color plays an important role. It helps in tasks such as object recognition. In humans, color perception starts with cones in the retina. Studies in the primary visual cortex show opponent mechanisms for color representation. Whi...

We report the results of psychophysical experiments on color contrast induction. In earlier work [Vision Res. 34, 3111 (1994)], we showed that modulating the spatial contrast of an annulus in time induces an apparent modulation of the contrast of a central disk, at isoluminance. Here we vary the chromatic properties of disk and annulus systematically in a study of the interactions among the lum...

Although color-opponent neurons appear to subserve color vision, precisely how these cells encode hue is still not clear. Single-unit, extracellular recordings from the rainbow trout optic tectum were made in order to examine the possible role of action potential timing in coding chromatic stimuli. We found that color-opponent units can exhibit differences in response latency which are a functi...

THE RECEPTORS AND NERVE CELLS that make up the visual pathway must convey and interpret information on both the form and the color of retinal images. In higher mammals little is known about the degree to which nerve cells are specialized for handling these types of information. In a visual stimulus the importance of spatial attributes, and especially of dark-light contours, first became obvious...