System for compression and decompression of video data using discrete cosine transform and coding techniques
US5196946A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1990 |
| Grant date | Mar 23, 1993 |
| Priority date | — |
| Expiry date | Mar 14, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital video compression system and an apparatus implementing this system are disclosed. Specifically, matrices of pixels in the RGB signal format are converted into YUV representation, including a step of selectively sampling the chrominance components. The signals are then subjected to a discrete cosine transform (DCT). A circuitry implementing the DCT in a pipelined architecture is provided. A quantization step eliminates DCT coefficients having amplitude below a set of preset thresholds. The video signal is further compressed by coding the elements of the quantized matrices in a zig-zag manner. This representation is further compressed by Huffman codes. Decompression of the signal is substantially the reverse of compression steps. The inverse discrete cosine transform (IDCT) may be implemented by the DCT circuit. Circuits for implementing RGB to YUV conversion, DCT, quantization, coding and their decompression counterparts are disclosed. The circuits may be implemeneted in the form an integrated circuit chip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.