Rod influence on hue appearance of spectral lights was characterized by comparing the scaling of red, green, yellow, and blue hue sensations for an 8 degrees-diameter, 7 degrees-eccentric test spot under conditions that minimized (cone plateau) and maximized (dark adapted) rod influence at two mesopic light levels (1.5 and 3.0 log scoptic trolands). At the lower light level, the hue-scaling fun...

Hue provides a useful and intuitive cue that is used in a variety of computer vision applications. Hue is an attractive feature as it captures intrinsic information about the colour of objects or surfaces in a scene. Moreover, hue is invariant to confounding factors such as illumination brightness. However hue is not stable to all of the types of confounding factors that one might reasonably en...

Hue-naming was used in conjunction with a probe-flash procedure to determine the time-course of rod-mediated effects on hue appearance across the spectrum. Two types of rod influence on hue are distinguishable on the basis of differences in both spectral specificity and time course of effect: (1) a "faster" rod influence enhances green relative to red and (2) a "slower" rod influence enhances s...

Unique hue settings of 185 observers under three room-lighting conditions were used to evaluate the accuracy of full and mixed chromatic adaptation transform models of CIECAM02 in terms of unique hue reproduction. Perceptual hue shifts in CIECAM02 were evaluated for both models with no clear difference using the current Commission Internationale de l’Éclairage (CIE) recommendation for mixed chr...

Color intensity projections (CIP) have been shown to improve the visualisation of greyscale angiography images by combining greyscale images into a single color image. A key property of the combined CIP image is the encoding of the arrival time information from greyscale images into the hue of the color in the CIP image. A few minor improvements to the calculation of the CIP image are introduce...

PURPOSE To use a theoretical model of the observer on the Farnsworth-Munsell 100-hue test to estimate the magnitude of random variation in 100-Hue test error scores. METHODS The model was based upon classical signal detection theory. Results from the model were obtained by computer simulation. RESULTS There is a fairly regular relationship between mean test scores over many tests and the st...

Novel tools for colour image processing are presented. Unlike many magnitudes dealt with in engineering, the hue variable of a colour image is circular and requires a special treatment. Special techniques have been advanced in statistics for the analysis of data from angular variables; likewise in image processing for the processing of the hue variable. We give a definition of the median and of...

This paper employs uniform color space to analyze relations in dichromacy (protanopia, deuteranopia, tritanopia). Fifty percent or less of dichromats represent the classical reduction form of trichromacy, where one of three cones is inoperative but normal trichromatic color mixture such as complementary colors (pairs that mix white) are accepted by the dichromat, whose data can thus be plotted ...

Spectroradiometric color measurements were performed at 26 regularly spaced points of a standard wine sampler into which 100 cc of wine were poured. Our goal is to describe the color changes occurring in this system, but not to propose a new method for wine-color measurement. Three samples of three different wines (red, rosé and white) were studied. From experimental measurements, lines of cons...