Perceptually-adapted image coding system
US5517581A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1995 |
| Grant date | May 14, 1996 |
| Priority date | — |
| Expiry date | Apr 5, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image-coding system reduces image data redundancies and perceptual irrelevancies through progressive sub-band coding. The image is separated into a plurality of sub-bands. From this sub-band information, a perceptual metric, based on the properties of the sub-band filters, quantizer error distribution, and properties of the human visual system, is determined which provides the maximum amount of coding noise that may be introduced to each pixel in every sub-band without causing perceptible degradation of the coded image. This perceptual metric is used to adjust the quantizer used in encoding each sub-band signal. In addition, redundancy in the output of the quantizer is reduced using a multidimensional Huffman compression scheme.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.