Inventors:
Steve A. Jacob - Boise ID
David A. Johnson - Boise ID
Assignee:
Hewlett-Packard Company - Palo Alto CA
International Classification:
G03F 308
Abstract:
The method of the invention provides an improved method for converting primary printer color values to combinations of the primary printer color values and black to achieve improved printer output color representations. The method includes the following steps. A first balanced set of primary printer color combinations (e. g. , CMY) is initially derived which provides a balanced gray representation at various levels of primary color concentration. A second balanced set of primary printer color combinations (e. g. , CMYK) is derived which provides a balanced gray representation at various levels of color concentration. Next, a set of primary printer colors (CMY) with K is derived, using the first balanced set, which best represents shadow colors, and a maximum color value is chosen therefrom. Then, a similar set of primary printer colors is calculated which best represents highlight values, by interpolating from the chosen maximum color value to a white value. CMYK color values are then determined, using the second set, shadow colors and highlight colors, which represent regions between black, white and maximum color points already found.