TY - JOUR
T1 - Fast encoding method for vector quantization using modified L2-norm pyramid
AU - Pan, Zhibin
AU - Kotani, Koji
AU - Ohmi, Tadahiro
PY - 2005/9
Y1 - 2005/9
N2 - The L2-norm pyramid has already been investigated as a promising data structure for the fast search of vector quantization (VQ) encoding in the previous work. Because the distortion at the top level is always tested first when using such a conventional L2-norm pyramid, the top level is most important. In order to enhance the capability of achieving a rejection decision at the top level, a modification is introduced into the conventional L2-norm pyramid in this letter by using both the mean and the variance of a vector simultaneously to replace the L2-norm of the vector for distortion computation at the top level. Two issues are made clear as 1) why this modification is beneficial to the distortion test is proved and 2) why only the top level of a conventional L2-norm pyramid should be modified is interpreted as well. Experimental results confirmed that the performance of VQ encoding by using the modified L2-norm pyramid can be improved obviously.
AB - The L2-norm pyramid has already been investigated as a promising data structure for the fast search of vector quantization (VQ) encoding in the previous work. Because the distortion at the top level is always tested first when using such a conventional L2-norm pyramid, the top level is most important. In order to enhance the capability of achieving a rejection decision at the top level, a modification is introduced into the conventional L2-norm pyramid in this letter by using both the mean and the variance of a vector simultaneously to replace the L2-norm of the vector for distortion computation at the top level. Two issues are made clear as 1) why this modification is beneficial to the distortion test is proved and 2) why only the top level of a conventional L2-norm pyramid should be modified is interpreted as well. Experimental results confirmed that the performance of VQ encoding by using the modified L2-norm pyramid can be improved obviously.
KW - Conventional L-norm pyramid
KW - Fast encoding
KW - Modified L-norm pyramid
KW - Vector quantization (VQ)
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U2 - 10.1109/LSP.2005.851263
DO - 10.1109/LSP.2005.851263
M3 - Article
AN - SCOPUS:27644594388
VL - 12
SP - 609
EP - 612
JO - IEEE Signal Processing Letters
JF - IEEE Signal Processing Letters
SN - 1070-9908
IS - 9
ER -