France Telecom

Telediffusion De France

Etat Francais (cnet)

Jean-Claude Carlac'h

Emmanuel Cadic

Pierre Siohan

Pierre Duhamel

Jean-Pierre Tillich

Lionel Guivarch

Iryna Andriyanova

Christine Guillemot

A coding method is provided for associating redundant and source data and for carrying out a plurality of local codes associating at least one input status word and at least one output status word according to at least one label word and permutations applicable on at least certain of said words. The local codes are embodied in the form of detection codes and not error correction codes on a predetermined coding alphabet. The local codes are interconnected by the status words in such a way that at least one coding matrix is formed, each of which defining a base code.

Error-correction coding method comprising local error detection codes interconnected by state words, corresponding decoding method, transmitting, receiving and storage devices and program

The invention relates to an error correction coding method, using at least two distinct sections of a predetermined elementary code, associating an arrival vector (s, s) with a starting state vector (s, s), according to a vector of branch labels (b, b, b, b), defining a code word, two sections of said elementary code being distinct when the order and/or the role of the elements of said branch label vector are changed.

Error correction coding method using at least twice a same elementary code, coding method, corresponding coding and decoding devices

The invention concerns a method for decoding received digital data corresponding to transmitted digital data coded with an entropic code associating with each word of an alphabet a distinct bit sequence, whereof the length is a function of said word occurrence probability, using a decoding lattice whereof each transition corresponds to a binary value 0 or 1 of one of the bits of a sequence corresponding to one of said words.

Method for decoding data coded with an entropic code, corresponding decoding device and transmission system

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.

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Rennes, France

Jean-Claude Carlac'h