Adaptive tree-search vector quantization in MPEG2 decoder
US6320907A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1998 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Nov 19, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/94
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The memory requirement of MPEG decoders and SQTV/IQTV systems may be reduced by recompressing the MPEG decoded data stream before storing pixels in an external RAM. An efficient compression method for recompressing video picture data based on the tree-search vector quantization (TSVQ) is made more effective by optimizing the way the quantizer is chosen for quantizing the differences among adjacent pel vectors. This method is based on premultiplying a read-only table using quantized complexity measures relative to the centroids of the tree-like scheme used in the TSVQ processing. A plurality of precalculated tables of quantization of the prediction error of a physical parameter of blocks of digital data are produced. For each one of the regions in which a block is divided, the calculated and quantized complexity measure provides an address that selects the most appropriate precalculated table for quantizing the prediction error. The adaptive tree-search vector quantization method is implemented in a corresponding hardware architecture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.