Ry. Wang et al., CODEBOOK ORGANIZATION TO ENHANCE MAXIMUM A-POSTERIORI DETECTION OF PROGRESSIVE TRANSMISSION OF VECTOR QUANTIZED IMAGES OVER NOISY CHANNELS, IEEE transactions on image processing, 5(1), 1996, pp. 37-48
We describe a new way to organize a full-search vector quantization co
debook so that images encoded with it can be sent progressively and ha
ve resilience to channel noise, The codebook organization guarantees t
hat the most significant bits (MSB's) of the codeword index are most i
mportant to the overall image quality and are highly correlated. Simul
ations show that the effective channel error rates of the MSB's can be
substantially lowered by implementing a maximum a posteriori (MAP) de
tector similar to one suggested by Phamdo and Farvardin, The performan
ce of the scheme is close to that of pseudo-gray coding at lower bit e
rror rates and outperforms it at higher error rates, No extra bits are
used for channel error correction.