Visual communication[s] and image processing '91 : visual communication, 11-13 November 1991, Boston, Massachusetts - Tzou, Kou-Hu; Koga, Toshio; Society of Photo-optical Instrumentation Engineers; IEEE Circuits and Systems Society; IEEE Acoustics, Speech, and Signal Processing Society; European Association for Signal Processing (Proceedings / SPIE -- the International Society for Optical Engineering, 1991)