Abstract: The decompression side of the system has apparatus for forming a sequence of arrays of pixel display values for driving a display device from a stream of compressed data containing compressed data codes. Each of the arrays of pixel display values represents a frame of a moving image. Pixel copy codes within the stream of compressed data trigger copying of one or more previously formed pixel display values to a current position within a sequence of positions within the array along which decompression progresses. New pixel codes within the stream of compressed data trigger mapping of one or more pixel appearance values specified by the new pixel codes to respective pixel display values. The pixel display values derived from the new pixel codes are then written to a current position within the sequence. The compression side provides a complementary mechanism for generating such pixel copy codes and new pixel codes from source image data.

Abstract: A signal generator generates a plurality of grey level signals which are inputted into a one bit-per-pixel raster scan video display device (such as a simple matrix liquid crystal display). Each grey level signal causes a particular proportion of pixels to be illuminated, in order to produce a particular grey level. Uniform high quality grey levels are produced by introducing into each grey level signal a variable frame phase shift for successive rows of each frame. The specific phase shifts introduced between successive rows and frames result in the illuminated pixels being distributed evenly in each frame. The pattern of illuminated pixels changes smoothly with time to produce the required uniform high quality grey level.