Video signal quantization for an MPEG like coding environment
US5214507A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Nov 8, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/152
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A quantization parameter for use in encoding a region of an image is developed from a) a categorization of the region into one of a predetermined plurality of perceptual noise sensitivity (PNS) classes, b) a level of psycho-visual quality that can be achieved for the encoded version of the image, the level being selected from among a plurality of predetermined levels, and c) a prestored empirically derived model of the relationship between the PNS classes, the psycho-visual quality levels and the values of the quantization parameter. PNS indicates the amount of noise that would be tolerable to a viewer of the region, i.e., the perceptual sensitivity of the region to noise. Some characteristics on which PNS classes may be based are: spatial activity, speed of motion, brightness of the region, importance of the region in a particular context, the presence of edges within the region and the texture of the region, e.g., from "flat" to "highly textured". PNS classes that include combinations of the characteristics of a region of the image may also be defined. The PNS classes employed are selected by the implementor and may be determined empirically. The psycho-visual quality of an encod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.