Adaptive image data compression
US6724817B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2000 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Dec 10, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and apparatus for compressing an image data signal. The apparatus includes a compression control module arranged to eliminate frequency components produced from the image data signal which have a magnitude less than a threshold value. The apparatus compares the volume of the compressed image data signal with a target volume and selects to increase or decrease the applied compression level depending on the outcome of the comparison. The compression level is increased by increasing the threshold value and deacreased by decreasing the threshold value. The compression level, or ratio, is thus adaptable in real-time in order to meet a target volume for the compressed image. This is particularly advantageous in applications where, for example, the compressed image signal is to be transmitted over a fixed bandwidth link. The method and apparatus of the invention are particularly suitable for use in the implementation of the JPEG basline image compression standard.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.