Progressive image decoder for wavelet encoded images in compressed files and method of operation
US6587588B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1999 |
| Grant date | Jul 1, 2003 |
| Priority date | — |
| Expiry date | Dec 16, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/645
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A progressive image display decoder and method of operation for wavelet encoded images achieves reduced memory storage requirements for wavelet transform coefficients and reduced execution time in displaying the image thereby overcoming the limitations of the prior art. Conveniently, a wavelet image format, typically DjVu IW44 facilitates progressive rendering and smooth scrolling of large color or gray level images with limited memory requirements. The progressive wavelet decoder is composed of two components. The first component decodes the incoming image data and updates an array of wavelet coefficients. The second component applies an inverse wavelet transform to the array of wavelet coefficients for the purpose of reconstructing the image. The operation of the first component (the decoder) is triggered by the incoming compressed image data. The received data is decoded and is used to apply updates to an array of wavelet coefficients. Each update improves the accuracy of the coefficients and therefore improves the fidelity of the reconstructed image. The coefficient array is composed of several two-dimensional arrays (one for each of the color components) having one entry corre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.