Adaptive type quantizer
US4386366A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 16, 1981 |
| Grant date | May 31, 1983 |
| Priority date | — |
| Expiry date | Mar 16, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for adaptively equalizing sampled input picture element values in which an estimation error obtained from a sampled input picture element value and the estimation value thereof are adaptively quantized by selecting one of a plurality of quantization characteristics. Quantization steps are determined in accordance with the desired quantization characteristics. Input groups of picture elements are divided into adjacent blocks and a quantization characteristic used for succeeding blocks is determined according to the distribution of quantization level values of preceding blocks. A quantization characteristic selecting unit selects a quantization characteristic set by the quantization characteristic determining unit from among a plurality of quantization characteristics. The estimation errors are quantized in a predetermined block using the quantization characteristic which is so selected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.