Efficient wavelet-based compression of large images
US6546143B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1999 |
| Grant date | Apr 8, 2003 |
| Priority date | — |
| Expiry date | Mar 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/645
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A subband decomposition of an image is performed by filtering the image in a progression of N line windows. In a first filter stage, vertical filters perform high and low pass filtering on each N line window. Then horizontal filtering is performed on the output of each vertical filter. The lowest subband provided by the filter stage is recursively decomposed by additional filter stages. Higher subbands of each filter stage are encoded and placed in an embedded bitstream. Block encoding can be performed in which a number of lines of each subband are coded as a plurality of blocks. The blocks of a subband are coded independently of each other. The block coding supports region-of-interest reconstruction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.