Ordered dither patterns for coarse quantization of pictures
Bernard Lippel, M. Kurland, Anthony Hugh Marsh · Proceedings of the IEEE · 1971
It is well known that a coarse quantizer can be used for pulse-code modulation (PCM) picture transmission when random dither is added to the video, and that synchronous dither subtraction at the receiver significantly improves picture quality. Two-dimensional ordered dither patterns are reported and illustrated which provide better picture quality than equivalent random dither and which do not require synchronous subtraction.