Patent Document ID: 4488245
Application ID: 06366027
Patent Status: 1

Claim One:
1. A method of color detection and modification for use in the processing of colored images, comprising the steps of: a. selecting a set of parameters to define color variations, comprising one parameter which varies at least approximately with luminance and two other parameters varying with chromaticity; b. deriving sets of signals based on these parameters representing sample points on a sample curve defining the variations of chromaticity throughout the luminance range of the samples, along which curve maximum correction is required; c. obtaining a succession of sets of input signals based on said parameters, each set representing an element of the original image to be reproduced; d. obtaining from each of said sets of input color signals (1) a luminance factor signal; (2) chromaticity deviation signals representing the differences respectively between the signal values for the said other two parameters of the obtained set and their respective values on an extended curve which extends from the said sample curve to cover the entire luminance range of the input color signals, the values being taken at a point on the curve defined by the luminance value of the obtained set of signals; (3) deriving from the chromaticity deviation signals and the luminance factor signal a weighting signal whose value is a predetermined function of said signals. e. combining each of a predetermined set of color correction values with the weighting signal to derive a set of modified color correction values; f. combining each of the said set of modified color correction values with its corresponding set of input color signals to produce corrected output color signals; and g. wherein the succession of sets of output color signals represents the original image with selective color enhancement.