The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 1991
Filed:
Apr. 18, 1990
Christine Guillemot, Rennes, FR;
Jean-Claude Carlac'h, Rennes, FR;
Pierre Duhamel, Issy Les Moulineaux, FR;
Etat Francais (CNET), Issy Les Moulineaux, FR;
Telediffusion de France, Montrouge Celex, FR;
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.