The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 09, 2000
Filed:
Mar. 25, 1997
William Chesley Decker, Longmont, CO (US);
Ho Chong Lee, Endicott, NY (US);
Jack Louis Zable, Niwot, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system, method, and program of the invention determine a unique combination of four colorants (C'M'Y'K') of a given printer that is equivalent to an externally defined four colorant combination (CMYK) by having the same color values (e.g., L*a*b* values). L*a*b* values associated with each three component combination (CMY) with the fourth component value (K) equal to zero of the externally defined four colorant combination (CMYK) are used in an inversion/interpolation program The printer also prints out a matrix of predetermined varying combinations of the three colorants of the printer (CMY)p with the fourth colorant K equal to zero. L*a*b* values are measured for each patched. These values and the corresponding three colorant combination values are inputted into the inversion/interpolation program. For any given externally defined three colorant combination (CMY), or L*a*b* value, a corresponding three colorant combination (C'M'Y') of the printer can be determined from the inversion/interpolation program by matching L*a*b* values. Then, a fourth colorant, e.g., black, (K) of the externally defined four colorant combination is mapped to an equivalent fourth colorant (K') of the printer by matching color values (e.g., L*). For example, the L* value is found for various percentages of the fourth colorant through standard tables where C=0, M=0, Y=0. The L* value is found for various percentages for the fourth colorant of the printer by printing varying percentages of the fourth component and measuring its L*a*b* values and, assuming a* and b* are near zero, using the L* value. As such, the conversion takes place in two steps, from CMY to C'M'Y' and from K to K'.