Transcoder and coded image conversion method
US8204105B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 6, 2007 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Apr 4, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A quantization step determination part inputs an evaluation value (ACT_MB) indicating the dispersion in a macroblock and its average value (ACT_PIC). A subtracter obtains the difference between these values, and a multiplier multiplies the difference by raq (<1) to obtain a weighting value. Next, an adder adds the weighting value to an average quantization step value of source data, and finally a multiplier multiplies the sum by a step value adjustment factor α (>1) to obtain a converted quantization step value (Qstep_AVC). This optimizes a bit allocation in accordance with an Activity value of the macroblock, to thereby improve the quality of image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.