Patent ID: 6118548
Filing Date: 2000-09-12
Classification: B41J,G06K,H04N

Abstract:
A print driver in which image data for black pixels is replaced with process black for all pixels in each M row by N column region surrounding a target pixel in the event that the target pixel is a color pixel, comprising:a first identifying step of identifying location of the first color pixel in a current replacement window of a current raster line, said first identification step testing multiple pixels simultaneously in groups so as to determine whether a group contains a color pixel;a second identifying step of identifying location of the last color pixel in the current replacement window of the current raster line, said second identifying step testing each Nth subsequent pixel to the first color pixel until encountering a pixel that is not color; andreplacing image data for black pixels with image data for process black for all pixels between the first and last color pixel plus a margin, for each of M raster lines centered on the current raster line.