Encoding method and apparatus to determine quantization levels using energy characteristics in the DCT domain
US5489944A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 13, 1994 |
| Grant date | Feb 6, 1996 |
| Priority date | — |
| Expiry date | Apr 13, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/152
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An encoding method and apparatus uses energy characteristic of discrete cosine transform (DCT) domains for determination of a quantization level. The DCT domain is divided into for sub-domains. The energy characteristic of each macroblock is represented as one among the four domains such as simple, complicated, edge and plain domains. The buffer generates a first quantization level which is varied according to the buffer fullness in units of a slice. The energy characteristic information and the first quantization level of the buffer are used for determination of a second quantization level supplied to a quantizers. The quantizers quantize the transformation coefficient data according to the second quantization level generated in units of the macroblock. Thus, the viewer can feel less quantization error in sight. The encoding apparatus generates a second quantization level by only addition operation of the varied value of the first quantization level which is determined by the energy characteristic information to the first quantization level, thereby providing a quantization level generator capable of being implemented with simple hardware.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.