Image processing system for compressing image data including binary image data and continuous tone image data by a sub-band transform method with a high-compression rate
US6714685B2 · kind B2 · utility
6Cited by
11References
5Claims
0Family size
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Key dates
| Filing date | Apr 28, 2003 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | May 4, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/007
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
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