Quantization control circuit
US5389973A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1993 |
| Grant date | Feb 14, 1995 |
| Priority date | — |
| Expiry date | Mar 29, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A quantization control circuit determines an optimum scaling factor for quantizing orthogonal transformation coefficient data that correspond to a predetermined time period of a digital video signal. A first scaling factor is determined from the orthogonal transformation coefficient data as a function of whether a bit rate determined by quantizing the orthogonal transformation coefficient data using an initial scaling factor is greater than a target bit rate. A corrected scaling factor is determined by calculating second scaling factors that are each derived from the first scaling factor. Error values are calculated from the second scaling factors using the orthogonal transformation coefficient data, and the second scaling factor that corresponds to the minimum error value is selected as the corrected scaling factor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.