Patent ID: 6775030
Filing Date: 2004-08-10
Classification: H04N

Abstract:
A method for producing a color space transformation, which comprises:converting color values of a first printing process into color values of a second printing process to substantially transfer black build-up of the first printing process into the second printing process and to make a visual impression of printed colors in both printing processes be substantially the same by: characterizing color reproduction characteristics of the first printing process with a first color profile specifying an association between device dependent color values of the first printing process and color values of a device independent color space; characterizing color reproduction characteristics of the second printing process with a second color profile specifying an association between device dependent color values of the second printing process and color values of a device independent color space; determining a first lightness curve from the first color profile; determining a second lightness curve from the second color profile; calculating an inverted lightness curve from the second lightness curve; linking the inverted lightness curve and the first lightness curve to form a first transformation function; determining second transformation functions from the first color profile; determining third transformation functions from the second color profile; calculating inverted transformation functions from the third transformation functions; linking the inverted transformation functions and the second transformation functions to form fourth transformation functions; and joining the fourth transformation functions to the first transformation function to form a color space transformation between color values of the first printed process and color values of the second printing process.