| US 7,489,815 B2 | ||
| Source device to destination device transform using black weight | ||
| John S. Haikin, Fremont, Calif. (US); and Todd D. Newman, Palo Alto, Calif. (US) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan); and Microsoft Corporation, Redmond, Wash. (US) | ||
| Filed on Jan. 18, 2005, as Appl. No. 11/39,492. | ||
| Prior Publication US 2006/0159334 A1, Jul. 20, 2006 | ||
| Int. Cl. G06K 9/00 (2006.01); H04N 1/60 (2006.01) | ||
| U.S. Cl. 382—167 [358/518] | 29 Claims |
| 1. A color management method for converting source color data in a source device color space that might or might not include
a black channel to destination color data in a destination device color space that includes a black channel, the method comprising
the steps of:
obtaining a black weight of the source color data in the source device color space, wherein the black weight is obtained by
using a black channel of the source color data if the source device color space includes a black channel, and is obtained
by using color purity of the source color data if the source device color space does not include a black channel;
transforming the source color data into color data in a device-independent color space;
mapping the color data in the device-independent color space within a color gamut of the destination device;
selecting a LUT from among plural LUTs, wherein each LUT corresponds to a different black channel value, and wherein the selected
LUT corresponds to the obtained black weight; and
calculating destination color data in the destination device color space that includes a black channel, by using the mapped
color data and the selected LUT.
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