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This paper proposes a new bit allocation algorithm, capable of efficiently allocating a given quota of hits to an arbitrary set of different quantizers. This algorithm is useful in any coding scheme which employs hit allocation or, more generally, codebook allocation. It produces an optimal or very nearly optimal allocation, while allowing the set of(More)
for the mean-square quantizing error where N is the. number of level&p(x) is the probability density of the input, and E’(x) is the slope of the compressor curve. The formula, an approximation based on the assumption that the number of levels is large and overI& distortion is negligible, is a useful tool for analytical studies of quantfzation. This paper(More)
A pseudo-gray code is an assignment of n-bit binary indexes to 2” points in a Euclidean space so that the Hamming distance between two points corresponds closely to the Euclidean distance. Pseudo-Gray coding provides a redundancy-free error protection scheme for vector quantization (VQ) of analog signals when the binary indexes are used as channel symbols(More)
Vector quantization (VQ) provides many attractive features for image coding with high compression ratios. However, initial studies of image coding with VQ have revealed several difficulties, most notably edge degradation and high corhputational complexity. We address these two problems and propdse a new coding method, classified vectof quantization (CVQ),(More)
AbstrucfAn adaptive postfiltering algorithm for enhancing the perceptual quality of coded speech is presented. The posffilter consists of a long-term postfilter section in cascade with a shortterm postfilter section and includes spectral tilt compensation and automatic gain control. The long-term section emphasizes pitch harmonics and attenuates the(More)