Wave image compression
US6934420B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2000 |
| Grant date | Aug 23, 2005 |
| Priority date | — |
| Expiry date | Dec 3, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of image compression comprises the steps of recursively transforming a image using a Discrete Wavelet Transform. This creates a plurality of levels including at least a first level, multiple intermediate levels, and a low-low pass subband of the last level. The transformed image at each level is quantized, and datapacking the quantized image is performed. The step of datapacking further includes, encoding of the first level using adaptive run length of zero cofficients; encoding of the intermediate levels using run-length coding of zero coefficients and a predetermined two-knob huffman table for non-zero coefficients and encoding of the low-low pass subband using a low frequency packing algorithm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.