Digital video compression system and methods utilizing scene adaptive coding with rate buffer feedback
US4394774A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1981 |
| Grant date | Jul 19, 1983 |
| Priority date | — |
| Expiry date | Jun 26, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital video compression and expansion system and its methods for compressing and expanding digitalized video signals in real time at rates up to NTSC color broadcast rates are disclosed. The system compressor receives digitalized video frames divided into subframes, performs in a single pass a spatial domain to transform domain transformation in two dimensions of the picture elements of each subframe, normalizes the resultant coefficients by a normalization factor having a predetermined compression ratio component and an adaptive rate buffer capacity control feedback component, to provide compression, encodes the coefficients with a minimum redundancy coding scheme and stores them in a first rate buffer memory asynchronously at a high data transfer rate from which they are put out at a slower, synchronous rate. The compressor adaptively determines the rate buffer capacity control feedback component in relation to instantaneous data content of the rate buffer memory in relation to its capacity, and it controls the absolute quantity of data resulting from the normalization step so that the buffer memory is never completely emptied and never completely filled. In expansion, the sy…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.