METHOD FOR CONVERTING UNPRINTABLE COLOR VALUE INTO PRINTABLE COLOR VALUE, PICTURE REPRODUCTION SYSTEM FOR REPRODUCING COLOR PICTURE, AND CONTROL MEANS PROVIDED WITH COLOR CONVERSION MEANS FITTED TO THE SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce the influence of non-linearity in a boundary form against the decision of a second color coordinate by extending only a boundary part positioned far from a first color coordinate in a color space in the nearest part of the boundary in accordance with a distance from the boundary of the first color coordinate and obtaining the second color coordinate, based on the extending part of the boundary. SOLUTION: The minimum distance X from a color value 31 which is to be converted into a color range 17 to the nearest color value of a boundary 19 is decided. The minimum distance X forms a minimum range viewed from the color value 31 shown by a circle 32. Then, a second circle 33 having a radius larger than that of the first circle 32 by a value obtained by dividing the minimum distance X by N is decided. The first and second ranges which are thus decided form a margin where the color value positioned on the inner boundary 19 is selected in the color range 17. The color value with which the color value 31 is to be converted is decided by using the color value shown by a thick line 34 positioned on the mergin.