Title :
Anti-Pseudo-Gray Coding for VQ Encoded Images over Noisy Channels
Author :
Tseng, Hsien-Wen ; Chang, Chin-Chen
Author_Institution :
Dept. of Inf. Manage., Chaoyang Univ. of Technol., Taichung
fDate :
5/1/2007 12:00:00 AM
Abstract :
In this paper, an improved VQ index reassignment algorithm is proposed to reduce the block degradation of VQ encoded images caused by noisy channels. By reassigning the indices of a VQ codebook, the VQ-compressed images can be transmitted through a noisy channel while preserving the quality of reconstructed VQ images. Pseudo-Gray coding (PGC) and anti-Gray coding (AGC) are two famous index reassignment schemes. By combining the virtues of PGC and AGC skillfully, a novel VQ reassignment algorithm is proposed. Experimental results show that the proposed algorithm outperforms AGC and PGC. Additionally, the computational complexity of index reassignment in the proposed algorithm is reduced significantly
Keywords :
Gray codes; image coding; image reconstruction; source coding; vector quantisation; VQ encoded images; anti-Gray coding; anti-pseudo-Gray coding; image compression; image reconstruction; index reassignment algorithm; noisy channels; pseudo-Gray coding; vector quantization; Computational complexity; Cost function; Decoding; Degradation; Hamming distance; Image coding; Image reconstruction; Noise reduction; Source coding; Vector quantization;
Journal_Title :
Communications Letters, IEEE
DOI :
10.1109/LCOMM.2007.070074