Video image compression/decompression apparatus and method
US6535634B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 13, 1999 |
| Grant date | Mar 18, 2003 |
| Priority date | — |
| Expiry date | Aug 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/004
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of compressing a video image comprising a two-dimensional array of pixels, the image being divided into an array of contiguous blocks, the method comprising the steps of: (1) calculating, for each pixel within a block, a difference between a predicted luminance and an actual luminance; (2) assigning a frequency characteristic to the block based on a magnitude of the differences of the pixels within the block; (3) determining, for each pixel within the block, a quantized difference code based on the calculated difference and the assigned frequency characteristic; and (4) storing the frequency characteristic of the block and the quantized difference codes for each pixel within the block; and wherein the step of assigning comprises calculating a sum of the squares of the differences of all pixels within the block, and selecting the frequency characteristic from a set of predetermined frequency characteristics based on the calculated sum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.