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
US7295609B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 2002 |
| Grant date | Nov 13, 2007 |
| Priority date | — |
| Expiry date | Oct 10, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/44
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image information coding apparatus codes an input image signal in a manner optimized on the basis of the visual characteristics. In quantization, an input image signal is divided into blocks, an orthogonal transform is performed on a block-by-block basis, and resultant orthogonal transform coefficients are quantized. A quantizer includes a weighter for, in the quantization, performing weighting on each component of the orthogonal transform coefficients by means of an addition operation on a parameter specifying one of elements of a series of numbers arranged in accordance with a predetermined rule in correspondence with quantization step sizes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.