Process and device for the compression of image data by mathematical transformation effected at low cost, particularly for the transmission at a reduced rate of sequences of images
US5031038A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 18, 1990 |
| Grant date | Jul 9, 1991 |
| Priority date | — |
| Expiry date | Apr 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/147
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Process and device for the compression of image data by a mathematical transformation implemented at low cost, particularly for the transmission at reduced speed of sequences of images. The objective is to provide an economical method in "silicon area - processing speed" cost to implement a mathematical transformation of the DCT type, on arrays of pixels, suitable for image compression. According to the invention, the method consists essentially of combining a permutation (1) of each block of pixels with a series of one dimensional FFT (211, 213). A series of variants is obtained by adding or not adding steps of matrix calculation (22) of reconstitution of a complex 2D-FET, of rotations (3) of reconstitution of the DCT, and/or of suppression of the imaginary coefficients.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.