Patent Document ID: 5420704
Application ID: 08306428
Patent Status: 1

Claim One:
1. A method for correction of a color cast in a color original to be reproduced for color image processing, comprising the steps of: acquiring color values L*, a*, b* by point-by-point and line-by-line, trichromatic scanning of the color original with an image processing input apparatus; subdividing a value range of a luminance component L* of the color values L*, a*, b* into luminance regions; undertaking the subdividing into luminance regions in at least one of a light image region of relatively high luminance value and a dark image region of relatively low luminance value; additionally demarcating the luminance regions in view of chrominance by forming chrominance regions around a gray scale axis of a color space for analysis regions, and utilizing the analysis regions for checking for potentially present color casts; defining a minimum plurality of color values (L*, a*, b*) to be evaluated for identification of the color cast value in an analysis region; given presence of a color cast in an analysis region, making a determination as to whether a plurality of color values (L*, a*, b*) available in said analysis region is higher than said minimum plurality, and calculating the color cast value of the analysis region only when the plurality of color values (L*, a*, b*) available is higher than said minimum plurality; creating a characteristic final color cast value to be utilized for performing the color cast correction by at least one of selection or combination of the color cast values calculated for the individual analysis regions; and correcting the color values L*, a*, b* for color cast correction of the color original by use of the characteristic final color cast value.