Lossless near-lossless and lossy integrated cording based on lossless DCT

摘要

We propose a new coding method integrating 3 coding modes - lossless, near-lossless and 1ossy coding modes - under a unified single algorithm based on lossless DCT (L-DCT). In lossless mode, only the L-DCT and an entropy coder are used. In lossy mode, transformed coefficients of the L-DCT are quantized and then entropy coded as same as a conventional lossy method for compatibility. In this maruter, coding results are almost similar to these of the conventional lossy method except high bit rate because of rounding operation in the L-DCT Therefore, in near-lossless mode, we put quantization before the L-DCT to avoid the rounding effect. The tuning point between near-lossless mode and lossy mode is also theoretically analyzed. Simulation results cortf'trm effectiveness of our integrated system.