Fast loss less image compression system based on neighborhood comparisons
US6882750B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 27, 2003 |
| Grant date | Apr 19, 2005 |
| Priority date | — |
| Expiry date | Aug 12, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A fast loss less image compression system based on neighborhood comparisons compares pixel value differences with neighboring pixels and replaces such pixel values with the minimum of the differences. A marker is attached to a block of pixels, such that all the pixels in that block are compared with neighbors of one direction. The marker indicates how all of the pixels in that block are compared. Intermittent Huffman-tree construction is used such that one tree is used for several frames. Huffman coding is used to compress the resulting frame. A single Huffman-tree is constructed once every predetermined number of frames. The frequency of Huffman-tree construction can be performed according to the instantaneous availability of processor time to perform the construction. When more processing time is available, the Huffman-trees are computed more frequently. Such frequency variation can be implemented by using an input video frame buffer. If the buffer is a certain size, then processor time for Huffman-tree construction is available.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.