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. 19, 1996
Filed:
Oct. 05, 1992
Brigitte Ruetz, San Bruno, CA (US);
Canon Information Systems, Inc., Costa Mesa, CA (US);
Abstract
A method and apparatus for building and using tables which determine the colors to be printed from a device independent color coordinate system. Two tables are built: the first is a printer table for colors in the printer gamut as well as for colors in a typical color monitor gamut, and the second is a border table for colors outside the printer table. The printer table is constructed from a mathematically smooth mapping function for mapping from the device independent coordinate system (such as CIELAB space) to the printer coordinate system, and the mathematically smooth mapping function is determined based on a measurement of the printable colors in the device independent coordinate system. The border table is constructed so as to preserve the hue of unprintable colors but to increase saturation so as to achieve a more natural looking result. Transition colors are added to the printer table outside the printer gamut, smoothing the transition from the edge of the printer gamut to the border table. In use, either the printer table or the border table is selected based on whether the desired color in the device independent coordinate system is within the printer table or outside the printer table.