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:
Mar. 29, 1994
Filed:
Oct. 28, 1992
Brigitte Ruetz, San Bruno, CA (US);
Canon Information Systems, Costa Mesa, CA (US);
Abstract
Method and apparatus for color printing according to a printer table having high color smoothness for out-of-gamut colors. A color printer gamut edge is first determined and color primary values for colors within the printer gamut are calculated and inserted into the printer table. For transition colors, namely those colors outside the printer gamut edge but still within the printer table, color primary values are calculated by selecting a color from the printer gamut edge at a point which lies at a constant angle from the transition color in question. The same constant angle is used for each and every one of the transition colors. A border table is provided for colors outside of the printer table; the color primary values for the border table are selected in the same manner as for the transition colors. According to the invention, it is possible to provide smooth color transitions for out-of-gamut colors, and in particular it is possible to provide monotonically increasing lightness in both the printer table and the border table and thereby avoid undesirable bands of darker colors within lighter colors.