Method and apparatus for image coding
US6256343A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1997 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Oct 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an image coding such as the international standard H.263, when a motion compensated predictive error signal is orthogonal transformed, derived transform coefficients are quantized and coded, and a motion vector is coded, in order to be liable to detect a motion vector having a small amount of information, estimation is performed by subtracting a predetermined value from a fundamental evaluation value used for motion estimation only in case of a specific motion vector, it is set by a quantizing characteristic parameter for determining a quantizing step width when the transform coefficients are quantized so that the narrower the quantizing step width is, the smaller a difference value subtracted from the appreciation value is. Deterioration in prediction characteristic can be prevented and the amount of coding information of the motion vector accompanying the motion compensating method can be controlled in consideration of the whole coding information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.