Method and apparatus for video compression using block and wavelet techniques
US6031937A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 19, 1994 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | May 19, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/124
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are disclosed for symmetrically compressing and decompressing video information in real time by coupling block and wavelet techniques. In the compression pipeline, the image is divided into blocks comprising 2.sup.k .times.2.sup.k pixels (in the preferred embodiment, k=1). The average color of each block is computed. The system computes an average luminance for each block and differential luminances of each pixel of the plurality of pixels of each block. A first plurality of frequency details of each block are determined by Haar transforming the differential luminances. The system computes an average color difference between each block and the preceding block, and quantizes the average color difference and the first plurality of frequency details using Lloyd-Max quantization. In an alternate embodiment, skip codes are generated for blocks having the same quantized average color difference and second plurality of frequency details. The quantized average color difference and a second plurality of frequency details are encoded using variable length codes. The system employs lookup tables to decompress the compressed image and to format output pixels. The output …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.