Compression of image data seperated into frequency component data in a two dimensional spatial frequency domain
US5757973A · kind A · utility
51Cited by
6References
9Claims
0Family size
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Key dates
| Filing date | Dec 17, 1991 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Dec 17, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A data compression system decorrelates input data into sets of frequency component data. Different sets of frequency component data are entropy encoded using different coding tables matched to the data values characteristic of the sets of frequency component data they are used to compress. Matching the coding tables to the sets of frequency component data improves compression. The order in which the data values from within each set of frequency component data is fed to the entropy encoder is varied to exploit any intra-set correlation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.