Method for CCITT compression of image data

The invention generally relates to compression of digital image data. More particularly, the invention pertains to improved CCITT Group 4 image data compression. A method of compressing image data utilizing CCITT Group 4 coding criteria reduces compression time and the amount of required data transfer by combining pixel data thresholding and transposition steps through the capabilities of a customized processing chip. Additional economies are achieved by using black/white and white/black transition pointers rather than the conventional approach requiring examination of every pixel to locate the transitions in preparation for conventional CCITT Group 4 encoding.