Adaptive type compression method for compressing a color image by imparting predetermined variable-length codes to combinations of quantized values based upon quantized prediction error components
US4656500A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 27, 1984 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Apr 27, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/042
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive type compression method for a color image in which each sequence of picture elements obtained by combination of sum-difference transformation with DPCM is compressed by being multiplied by an adaptive zonal filter. The sum-difference transformation is used to simplify transformation of the image into a spatial frequency zone. The zone filter characteristic is adaptively selected according to a predetermined transmission bit rate (compression rate). Further, this zonal filter characteristic is set so as to correspond with luminance and color difference signals. According to this method, image information to be recorded can be arbitrarily selected and distortion of the image at compressing and reproducing can be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.