Embedded image coder with rate-distortion optimization
US6625321B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1998 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Jan 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A rate-distortion optimized embedding (RDE) coder optimizes rate-distortion performance by coding information bits in the order of their R-D slope. RDE allocates the available coding bits first to the information bit with the steepest R-D slope, which indicates the largest distortion decrease per coding bit. The resultant RDE bitstream can be truncated at any point and still maintain an optimal R-D performance. To avoid the overhead of coding order transmission, an expected R-D slope is calculated by both the encoder and the decoder from previous RDE coded bits. A probability estimation table from a QM arithmetic coder allows the R-D slope to be derived using a lookup table operation. The rate-distortion optimised embedding (RDE) coder significantly improves the coding efficiency over a wide range of bit rates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.