The variability of color-selective neurons in human visual cortex is considered more diverse than cone-opponent mechanisms. We addressed this issue by deriving histograms of hue-selective voxels measured using fMRI with a novel stimulation paradigm, where the stimulus hue changed continuously. Despite the large between-subject difference in hue-selective histograms, individual voxels exhibited ...

In color matching experiments with extracellular recordings from axon terminals of ganglion cells in the tectum opticum of immobilized goldfish, direction-selective ganglion cells were shown to be color-blind. Their spectral sensitivity is determined by a high positive input from the long wavelength-sensitive cones and weak opponent input from other cone types.

The Simulcheck method for evaluating the accuracy of color simulation tools in relation to dichromats is described and used to test three color simulation tools: Variantor, Coblis, and Vischeck. A total of 10 dichromats (five protanopes, five deuteranopes) and 10 normal trichromats participated in the current study. Simulcheck includes two psychophysical tasks: the Pseudoachromatic Stimuli Iden...

The effect of harmonious versus non-harmonious color combinations in one aspect of information visualization effectiveness is considered. One focus is the relative suitability of two competing paradigms for determining color combinations that are harmonious. A second focus is the suitability of using opposing (i.e., opponent) colors for feature presentation in information visualization. The eff...

Color vision impairment was examined in patients with type 2 diabetes mellitus (DM2) without retinopathy. We assessed the type and degree of distortions of individual color spaces. DM2 patients (n = 32), and age-matched controls (n = 20) were tested using the Farnsworth D-15 and the Lanthony D-15d tests. In addition, subsets of caps from both tests were employed in a triadic procedure (Bimler &...

The lateral geniculate nucleus is thought to represent color using two populations of cone-opponent neurons [L vs M; S vs (L + M)], which establish the cardinal directions in color space (reddish vs cyan; lavender vs lime). How is this representation transformed to bring about color perception? Prior work implicates populations of glob cells in posterior inferior temporal cortex (PIT; the V4 co...

Visual objects can be described by their color and by their color contrast. For example, a red disk in front of a white background appears "red with high color contrast," whereas a red disk in front of a slightly less-saturated red background will appear "red with low color contrast." This paper examines the visual response to color contrast in a cone-based color space. The stimulus consists of...

In this paper we present a novel watermarking scheme to generalize a previous proposal by the same authors [2]. In that paper to watermark the image amounts to process the colors in the picture as points in the Color Opponency space and to offset each one of them by a random vector. As an extra constraint, in order to avoid picture quality degradation, the offset applied should be such that a c...

introduction: discoloration of resin composites is a common reason for replacement of these restorations. the aim of this study was to eva-luate the influence of different light curing de-vices on color stability of a microhybrid resin composite. materials and methods: 80 disc-shaped speci-mens (8 mm in diameter, 2-mm height) were fabricated from filtek z250 resin composite. specimens were divid...