A Bit-Rate Adaptive Coding System Based on Lossless DCT

摘要

In this paper, we propose a bit-rate adaptive coding system basedon lossless DCT (L-DCT). Our adaptive coding system consists of threedifferent operation mode: loss- less, near-lossless and lossy codingmodes. Quantization is ap- plied in transform domain (after theL-DCT) and spatial domain (before the L-DCT) in lossy mode andnear-lossless mode, respec- tively. Our adaptive coding system canautomatically select its operation mode at a given bit rate becauseit contains a function to calculate the turning point betweennear-lossless mode and lossy mode from characteristic of inputsignal.