Digital image compression and transmission system visually weighted transform coefficients
US4780761A · kind A · utility
88Cited by
8References
14Claims
0Family size
Assignee
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Key dates
| Filing date | Jun 2, 1987 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Jun 2, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for compressing and transmitting a digital image signal over a limited bandwidth communication channel, transform codes the image values and quantizes the transform coefficients according to a two-dimensional model of the sensitivity of the human visual system. The model of the human visual system is characterized by being less sensitive to diagonally oriented spatial frequencies than to horizontally or vertically oriented spatial frequencies, thereby achieving increased compression of the image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.