Compression of video signals
US5214502A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Dec 19, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/102
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To enable a digital composite color video signal (NTSC or PAL) to be compressed directly, that is without dividing it into its components and compressing the components separately, the digital composite color video signal is decorrelated, for example by spatial sub-band filtering, to form data sets, for example sub-bands, representing dc luminance information, ac luminance information and dc chrominance information. The data sets are then quantized in accordance with respective quantization values from a quantization matrix, those quantization values being such that the amount of quantization of each of some of the data sets to which the dc luminance information and the dc chrominance information is at least predominantly confined is less than the average of the amounts of quantization of the remaining data sets. At least some of the quantized data sets are then entropy encoded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.