Picture coding method, picture decoding method, picture coding apparatus, picture decoding apparatus
US7912122B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2005 |
| Grant date | Mar 22, 2011 |
| Priority date | — |
| Expiry date | Nov 7, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The picture coding method according to the present invention is a picture coding method for coding a picture on a block-by-block basis through orthogonal transformation and quantization, and coding a quantization matrix that is used to derive quantization steps for frequencies of orthogonal transformation coefficients, the method comprising: calculating a difference value between each of frequency components included in the quantization matrix and a predetermined value corresponding to said each of the frequency components; and coding the difference value into a variable length code, wherein a code length of the variable length code is shorter as the difference value is smaller, or equal to a code length of a neighboring difference value of said difference value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.