| 摘要 |
<p>If we assume that images to be printed will consist of a combination of natural images and computer generated images, we would like the natural images to map to the closest printable colors, and the computer generated images to map to the saturated printer colors. Usually, we cannot tell the source of a color specification, so one algorithm must suffice for both conditions. A method to combine the two is presented. First, the printable colors are measured is some device independent color space, such as L*a*b*. Next, the range of colors from some reference color CRT, consisting of the colors from black to monitor saturates, and the colors between, then from saturates to white, and the colors between, are calculated. The saturates are assigned colors based on what printable color a user would like to get when the user asks for a saturated CRT color. A good choice would be the color space defined by CCIR 709, but any color space could be used. This gives us the printer's representation of the outer range of the color gamut of the CRT. Next, a table is generated which subsample all colors available to the specified color space. This table fills in entries within the color gamut of the target printer with the closest printable color. Colors out of the printer's gamut are represented by an averaging of the printable colors and of the outer range of colors assigned for the saturates. A requested color is converted to the reference color space, then looked up in the table, and the resulting color specification is sent to the printer.</p> |
