Method and apparatus for coding image information, method and apparatus for decoding image information, method and apparatus for coding and decoding image information, and system of coding and transmitting image information
US8139636B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2009 |
| Grant date | Mar 20, 2012 |
| Priority date | — |
| Expiry date | Mar 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/44
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image information decoding method for decoding compressed image information in an image decoding apparatus, which has been coded via a process including dividing an input image signal into blocks, performing an orthogonal transform on the blocks on a block-by-block basis, and quantizing resultant orthogonal transform coefficients. The decoding process includes performing, in a dequantization unit in the image decoding apparatus, dequantization such that a quantization parameter is weighted by an addition operation that adds the weight by addition, and the dequantization is performed on each chroma and luma component of the quantized coefficients using quantization step sizes, said luma component being weighted by the quantization parameter; and performing, in a transform unit in the image decoding apparatus, an inverse orthogonal transform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.