METHOD FOR LAYING OUT HALFTONE SCREENS IN COLOR PRINTING USING SHIFTED SCREENS
Original Publication Date: 1993-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
In general, the printing industry uses a technique called halftoning for printing continuous tone images with binary printers. For example, a black and white photograph on the front page of a newspaper actually consists of white, black and many intermediate grays. In order to print represent colors with black ink, the dark gray area is printed with many larger black dots positioned close to each other while the light gray area is printed with less number of smaller black dots positioned further apart from each other. Thus, when viewing papers from a normal distance, the different patterned dot densities are interpreted by a viewers eyes as different grays. An equivalent technique is adapted for electronic printing where the size of a halftone dot is controlled by varying the numbers of pixels in a halftone cell.