In the present study, the light responses of ganglion cells to chromatic stimulus were recorded from isolated retina of neonatal chick. It was found that for some non-color-opponent ganglion cells, the spatiotemporal patterns of the cells' light responses were related to the chromatic information that they received. When stimulus with some chromatic component was applied, some ganglion cells wo...

This paper introduces a new color model, RBW, which can be used as an intuitive user-interface for selecting colors in computer graphics systems. It is based on the red-green, blue-yellow, and white-black color axes. These axes are similar to the axes in opponent color theory, but their semantics are different: in the RBW model, the white-black axis mixes white or black into the color rather th...

sensitivity curve for 1° 200 ms. flashes on a white background may be a rather precise indicator of the functioning of the opponent-color system. Thus, although J. T. believed that his right eye was normal, the corresponding spectral sensitivity curve (continuous curve, Fig. 3) lies near the limit of the normal range, indicating that his right eye may have been partially affected by a similar d...

The signals in visual cortex that ultimately give rise to color perception remain poorly understood. Controversy has particularly surrounded one aspect of color's encoding in the visual system-opponent processing in primary visual cortex. Early single-unit studies suggested that V1 contains relatively few color-opponent neurons. Neuroimaging measurements, however, have suggested that such neuro...

Psychologically pure colors are colors that exhibit a homogeneous appearance on some dimension of perceived color. Purity of appearance is closely tied up with theoretical understandings of the three canonical color attributes of hue, saturation, and lightness. According to the dominant Hering opponent color framework, the hues red, green, blue, and yellow are distinctive and fundamental to all...

In an effort to understand the workings of the retinal receptive fields, Enroth-Cugell and Robson developed a mathematical model that utilized the difference-of-Gaussian (DOG) function, an equation in which the inhibitory portion of a receptive field is subtracted from the excitatory portion. Additions to the original Enroth-Cugell and Robson equation have been successful in modeling a twodimen...

Physiological studies of color have uncovered many puzzles. Here are four puzzles. First, neurons in the lateral geniculate nucleus (LGN; Fig. 1) are strongly color opponent, but the opponency does not correspond to Hering's fundamental opponent-color pairs (red–green, blue–yellow) (Webster et al., 2000); moreover, the color-tuning of the population of LGN cells is not balanced across color spa...

The non-linear nature of the human visual response to achromatic contrast is a key element to improve the performance in achromatic image coding. Expressing transform coefficients in the appropriate contrast units is relevant when some particular non-linear processing hasto be applied. In the achromatic case, the use of non-linear psychophysical models is straightforward since achromatic contra...

The lateral geniculate nucleus (LGN) is the primary thalamic nucleus that relays visual information from the retina to the primary visual cortex (V1) and has been extensively studied in non-human primates. A key feature of the LGN is the segregation of retinal inputs into different cellular layers characterized by their differential responses to red-green (RG) color (L/M opponent), blue-yellow ...

A new method of measuring simultaneous contrast, or chromatic induction, is introduced and used to test the hypotheses that induction results from either multiplicative or subtractive interaction of either like receptors or like second-stage, opponent mechanisms. Predictions derived from these hypotheses do not predict the outcome of the experiments as well as the traditional notion that induce...