Adaptive quantizer
US4467346A · kind A · utility
18Cited by
6References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 9, 1982 |
| Grant date | Aug 21, 1984 |
| Priority date | — |
| Expiry date | Mar 9, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/648
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptative quantizer for use with color images separates each color component for separate quantization and breaks up the input image into a plurality of blocks. A quantization characteristic determining unit determines the characteristic to be used for a given block according to the distribution of quantization level values obtained when an estimation error in a preceding block is quantized according to a particular quantization characteristic. The characteristic may be changed when the distribution of quantization level values is smaller than or exceeds given threshold values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.