An image data coding system, wherein an image data in a bit map form is divided into first and second groups, pixels in each group of which are distributed over the whole area of the image data in the bit map form. First and second coders respectively code the first and second groups of image data into...http://www.google.com.au/patents/US5177797?utm_source=gb-gplus-sharePatent US5177797 - Block transformation coding and decoding system with offset block division
