Adaptive quantization apparatus
US5561719A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1992 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | Nov 4, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is a signal representing an original image. A device generates a signal representing a predicted image original image. A subtracter derives a difference between the original-image signal and the predicted-image signal, and outputs the derived difference as a prediction error signal. The prediction error signal is transformed into a transform-resultant signal. The transform-resultant signal is quantized with quantization characteristics. An activity of the original image is derived from the original-image sign. An activity is derived from the prediction error signal. The quantization characteristics are controlled in response to both the original-image activity and the prediction-error activity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.