Improved spatial aided low delay Wyner-Ziv video coding by wavelet shrinkage
To tackle the problem of lacking auxiliary information while generating the side information, we have proposed a novel spatial aided low delay Wyner-Ziv video coding scheme in which the wavelet transformation is applied to generate the auxiliary information. However, there exists an inefficiency that lowers the coding performance. The inefficiency is that many wavelet coefficients having very small absolute value in the high-pass subbands and these small coefficients decrease the correlation between the source and the side information. The diminished correlation makes the bit error rate increased sharply and declines the performance of the channel decoding. This inefficiency is a widespread phenomenon among the wavelet based Wyner-Ziv video coding schemes. Therefore, we propose a scheme to remove these noises like coefficients in high-pass subbands by using a wavelet shrinkage method. In our method, a soft-thresholding operator which is based on the statistical properties of the high-pass coefficients is proposed. The result reveals that the correlation between the smoothed WZ frame and the side information is improved by using the wavelet shrinkage method. Accordingly, the R-D performance is also improved.