Picture signal coding apparatus
US4205341A · kind A · utility
56Cited by
7References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1978 |
| Grant date | May 27, 1980 |
| Priority date | — |
| Expiry date | Nov 14, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/98
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A frame of a gray-scaled picture is divided into blocks, in each of which the mean luminance of picture elements is used as a threshold value for comparison with each picture element signal to classify it into 0 or 1 according to its magnitude to provide a resolution component. From the resolution component and each picture element signal in the block are calculated two gray components; the resolution component and the two gray components are used as coded outputs for each block. The size of each block is changed in accordance with the property of the picture in the portion corresponding to the block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.