Efficient rendering of masks to a screened buffer using a lookup table

摘要

A method and system for expanding a pixel bitmap mask. The pixel bitmap mask (102) is expanded by the use of a lookup table (104) to create an m*n bit expanded mask, where m is the depth of a screen and n is the number of pixels described by the original pixel bitmap mask (102). The expanded mask is logically ANDed with a foreground screen (106). The inverse of the expanded mask is logically ANDed with existing data in a screen buffer (108). The results of the two AND operations are logically OR'd to create a new screen buffer that is eventually sent to a printer.