SNR Scalability Based on Wavelet

Abstract

Scalable video coding methods and flexible streaming approaches are required for adapting changing network conditions in real time. This work presents scalable video coding based on a wavelet scheme. With respect to encoding, a scalable video encoder encodes predictive residual coefficients into several layers of a bit-stream. The bit-stream of the enhancement layer is truncated at various bit-rates, according to the bandwidth of the network. The residual image is reordered to form wavelet blocks. Wavelet blocks are classified into three types, and the most significant coefficients in each type of block are preserved. After the coefficients are preserved, significant coefficients are encoded using the concept of the significant link. With respect to decoding, the bit-stream of the enhancement layer is combined with the bit-stream of the base layer to reconstruct a better quality video. Simulation shows that the proposed method outperforms MPEG-4 FGS by around 0.5 dB in terms of PSNR.