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:
Apr. 23, 1996
Filed:
May. 03, 1994
Francis E Bockman, San Diego, CA (US);
Paul H Dillinger, San Diego, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A technique of merging or 'matching' hue pages of a CRT and printer is used to map CRT control signals through a common perceptual space into printer control signals. The system (1) receives a color specification expressed as CRT control signals, (2) locates the specified color within the CRT perceptual gamut, (3) normalizes the two gamuts in perceptual space, (4) determines the relative position of the same color in the normalized CRT gamut, (5) declares that position to be the relative position of that color in the normalized printer gamut as well, (6) unfolds the normalization to determine the absolute position of the color in the actual printer gamut, (7) expresses that position in terms of printer-control signals, and then (8) applies those signals to the printer, to print the specified color. As a result that color, and color changes, specified in terms of CRT control signals are tracked in terms of both printer control signals and actual printer performance. The two device gamuts are in effect mapped to each other; the full gamuts of both are in effect merged. This new mapping preserves relative positions in color space--and thus the capability of the printer to reproduce distinctions between colors seen on the CRT that appear very closely similar. Such discrimination between colors very adjacent in color space is supported nearly throughout gamuts of both devices, even very near the lightness extrema and maximum-saturation point on a hue page. To facilitate processing, the normalized characterizations for the CRT and printer gamuts (taken as triangular) are approximated for each of 360 hue pages by single-point data representing lightness and chroma at the saturation point--or normalized lightness at that point--plus two common lightness extrema for the gamut solid.