Quantization method and system for video MPEG applications and computer program product therefor
US7301999B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2004 |
| Grant date | Nov 27, 2007 |
| Priority date | — |
| Expiry date | Apr 14, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/40
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Digital signals are converted between a first and second format by a conversion process including generating coefficients representing the digital signals. The coefficients may be discrete cosine transform coefficient generated during encoding/transcoding of MPEG signals. The coefficients are subject to quantization by generating a dither signal that is added to the coefficients before quantization to generate a quantized signal. Preferably, each coefficient is first subject to a first quantization in the absence of any dither signal added to generate an undithered quantized coefficient. If the undithered quantized signal is equal to zero the undithered quantized coefficient is taken as the output quantized signal. If the undithered quantized coefficient is different from zero, the dither signal is added and the dithered coefficient thus obtained is subject to quantization to generate the output quantized signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.