Adaptive compression of digital video data using different modes such as PCM and DPCM
US5376968A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1993 |
| Grant date | Dec 27, 1994 |
| Priority date | — |
| Expiry date | Mar 11, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Digital video signals are adaptively compressed for communication to a receiver. Superblocks, each containing a plurality of blocks of digital video data, are compressed using PCM, DPCM with a general motion vector for the entire superblock, and DPCM with a specific motion vector for each block contained within a superblock. The result of each compression mode is compared after accounting for overhead data, to determine which results in the least amount of data for each block. These blocks are assembled into a superblock, and compared together with necessary overhead and motion vector data to the same superblock processed using all PCM as well as the superblock processed using all DPCM. The comparison determines which compression mode produces the least amount of data for the superblock. The most compact superblock is selected for transmission. The transmitted superblocks are decoded by a decoder that recovers the necessary motion vectors and overhead information which identifies the type of compression used to provide the superblock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.