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:
Jun. 09, 1998
Filed:
Jan. 24, 1996
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
Three-dimensional LUTs produce a lightness signal L* from input color signals C, M and Y. The three-dimensional LUTs are respectively provided for four divisional sections of an input color signal K. A three-dimensional LUT switching device judges to what section a current value of the input color signal K belongs. A selector selects one of the LUTs in accordance with a judgment result. Similar processing is performed for chromaticity signals a* and b*. According to another aspect of the invention, three-dimensional LUT color converters produce color signals L.sub.2 *, a.sub.2 * and b.sub.2 * based on only input color signals C, M and Y. A position in the L*a*b* space of the color signals L.sub.2 *, a.sub.2 * and b.sub.2 * has a deviation from a position of color signals L.sub.1 *, a.sub.1 * and b.sub.1 * to be output actually. Based on an input color signal K, a one-dimensional LUT produces a lightness signal L.sub.3 *, which corresponds to the deviation. A color signal combining means produces final output color signals L.sub.1 *, a.sub.1 * and b.sub.1 * based on the color signals L.sub.2 *, a.sub.2 * and b.sub.2 * and the lightness signal L.sub.3 *.