Compression coding device and expansion decoding device for picture signal
US5184229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1989 |
| Grant date | Feb 2, 1993 |
| Priority date | — |
| Expiry date | Dec 1, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device for coding a picture signal by compression produces, when detected that the amplitude of data which has undergone two-dimensional orthogonal transform and then normalized has overflown, data specifying the normalized data in addition to coded data of the normalized data. A decoding device, therefore, is capable of accurately decoding original picture data despite the overflow. When a block of picture data lies in a predetermined range which occurs with relatively low probability, the picture data is transformed into coded data which includes a predetermined code. When the block of picture data does not lie in such a range, the picture data is converted into Huffman-coded data. This reduces the required capacity of a look-up table for coding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.