Method and apparatus for real time compression and decompression of a digital motion video signal using a fixed Huffman table
US5329313A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1993 |
| Grant date | Jul 12, 1994 |
| Priority date | — |
| Expiry date | Oct 1, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A bitstream representative of at least one digital video image is decoded in real time by providing a code-book index from the bitstream, applying the code-book index to an index table to determine an index value, and comparing the index value to a first predetermined threshold. A single fixed statistical table is used for a plurality of images. If the index value is greater than the predetermined threshold, then at least one current pixel is determined by copying a corresponding previous pixel into the location of at least one current pixel; otherwise the index value is applied to a vector table to determine at least one vector value and a current pixel is determined from the vector value and a corresponding previous pixel. A digital video image is encoded in real time by selecting at least one pixel for encoding and determining at least one difference value between the selected pixel and at least one corresponding previous pixel. An index value corresponding to the location in a table of the difference value is calculated. If the index value is equal to a first predetermined value then a run-length counter is incremented by a second predetermined value and the process is repeated…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.