Hybrid image compression with compression ratio control
US6567559B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1999 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Sep 10, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A block based hybrid compression method with compression ratio control. The input page is classified as SOLID, TEXT, SATURATED TEXT or IMAGE type, and the compression method most appropriate for each class is chosen on a block by block basis. The compression methods shown include Block Truncation Coding, Lossy or Lossless Differential Pulse Code Modulation, Run Length Coding and Discrete Cosine Transforms, but other algorithms may also be used. The compression ratio is dynamically controlled by selection of the compression algorithm, and by the adjustment of control parameters on a block by block or a row of blocks basis. The methods shown will execute very efficiently on a Texas Instruments TMS302C82 multiprocessing Digital Signal Processor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.