A HVS-Weighted Cosine Transform Coding Scheme With Adaptive Quantization
King Ngi Ngan, Kin Seong Leong, Harcharan Singh · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1988
An adaptive cosine transform coding scheme capable of real-time operation is described. It employs an adaptive quantization scheme where the quantizer range is dynamically scaled by a fedback parameter from the rate buffer. To take into account the human visual characteristics, human visual system (HVS) properties are incorporated into the coding scheme. Results showed that the subjective quality of the processed images is significantly improved even at a low bit rate of 0.15 bit per pixel (bpp). Two images were coded with the adaptive scheme achieving an average of 0.2 bpp with very little perceivable degragation.