Method and apparatus for vector quantization for real-time playback on low cost personal computers
US5467413A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 20, 1993 |
| Grant date | Nov 14, 1995 |
| Priority date | — |
| Expiry date | May 20, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A vector quantization method and apparatus which processes signal vectors constructed from digital image data (such as a digital video stream). The digital video stream is treated as a sequence of images, each represented by a rectangular array of pixels. The pixels are processed in blocks (typically 4.times.4 blocks) of two types, known as smooth blocks and detail blocks. The detail blocks contain the original image pixels, while the smooth blocks contain pixels from a subsampled version of the image. The pixels in the blocks are formatted into image vectors, again in two types. Each type of image vector is separately compressed using a vector quantization coder and a separate code book for each type. Smooth image vectors are compressed using a smooth code book and detail image vectors compressed using a detail code book. The compressed data stream is specially constructed, as a stream of code words for smooth and detail image vectors, updates to the code books, and mask bits that select the type of each code word, to facilitate real time decompression on low cost microprocessors. The coding operation can include interframe coding in which the mask bits are additionally coded so t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.