An improved LDPC coding scheme with motion decision for distributed video codec

In conventional distributed video coding (DVC), we exploit a random irregular check matrix to realize LDPC coding. However, for DVC this method does not fully exploit the character that the bits corresponding to this random matrix with different significance can be protected in different degrees. Therefore, in this paper we propose an improved LDPC coding scheme with motion decision to improve the LDPC decoding performance. Considering the movement of the objects in the video sequence, all of blocks in the frame are classified as different motion areas which need the protection with varying degrees. Meanwhile, we exploit the progressive edge-growth (PEG) algorithm to generate a Weight-Increasing Parity-Check (WIPC) matrix for LDPC coding. Finally, the corresponding bits of the pixels located in the motion areas could be mapped to the variable nodes with different degrees in the generated matrix to proceed decoding. The experimental results show that compared with the conventional LDPC coding scheme in DISCOVER, the PSNR gain for our proposed coding scheme can reach up to 0.6db.