A process for compressing a two dimensional array of data including at least one array block having a plurality of block rows and a plurality of block columns of pixels, each pixel having at least one associated intensity value. The process includes generating a delta frame associated with a pair of the block columns, the delta frame having a plurality of delta rows and delta columns of delta bits, one of the delta rows being a highest order row; determining a number of duplicate rows of the delta rows, each of the duplicate rows forming an identical row byte value having delta bits which have a predetermined relationship with the delta bits of the highest order row; recording information indicative of the number of duplicate rows; and developing compressed data including the information indicative of the number of duplicate rows of the delta frame.