Adaptive block transform image coding method and apparatus
US4774574A · kind A · utility
285Cited by
2References
14Claims
0Family size
Assignee
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Key dates
| Filing date | Jun 2, 1987 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Jun 2, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/124
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a method and apparatus for transmitting a digital image over a limited bandwidth communication channel, an image is block transformed to produce blocks of transform coefficients; the transform coefficients are quantized in accordance with a model of the visibility of quantization error in the presence of image detail; the quantized coefficients are encoded with a minimum redundancy code; and the coded, quantized transform coefficients are transmitted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.