发明名称 |
Adaptive transform coding by selecting optimum block lengths according to variations between successive blocks. |
摘要 |
<p>Subblocks of input digital samples are stored into a buffer at frame intervals and segmented into blocks having an integral multiple of the length of the subblock. Each block is encoded into transform coefficients and stored into a memory. Each coefficient is squared and those of the squared transform coefficients which correspond to high-frequency components of the input digital samples are summed and a minimum value is detected therefrom as corresponding to an optimum block length. Those transform coefficients which correspond to the optimum block length are selected from the memory and multiplexed with a signal representative of the optimum block length. In a modification, interblock differences are detected between successive transform coefficients of equal block length and squared. Those of the squared interblock differences which correspond to equal block length are summed, producing a set of squared sums for each block length. A variation is detected between a representative squared sum of a given set and a representative squared sum of a successive set to identify a block length which corresponds to the variation as an optimum block length.</p> |
申请公布号 |
EP0428156(A2) |
申请公布日期 |
1991.05.22 |
申请号 |
EP19900121798 |
申请日期 |
1990.11.14 |
申请人 |
NEC CORPORATION |
发明人 |
SUGIYAMA, AKIHIKO, C/O NEC CORPORATION;IWADARE, MASAHIRO, C/O NEC CORPORATION;NISHITANI, TAKAO, C/O NEC CORPORATION |
分类号 |
G10L19/02;G10L19/022;H03M7/30 |
主分类号 |
G10L19/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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