Abstract: Method and apparatus for the digital encoding of a first raw file, the method includes: a first step of capturing the raw file, the raw file being an audio and/or image and/or video file; a second step of encoding the captured raw file into a second file, in a proprietary format (P); then, a third step for re-encoding the second file into a third file in a compatible format (C).

Abstract: A Method for reducing the entropy of an original matrix, includes a step using a wavelet transformation of the original matrix into a transformed matrix, a quantisation coefficient corresponding to each wavelet level, the wavelet transformation being calculated in fixed point using a first number of digits at least equal to 1, for example 3 digits, after the point. Such a method is particularly advantageous for image compression.

Abstract: Method of differential compression of the values of a matrix, in which the reference cell is chosen in such a way that the difference between the initial value, contained in a cell to be compressed, and the decompressed value of the reference cell is a minimum.

Abstract: Method for encoding a series of symbols using several models of the arithmetic or range coder type and including steps where: each model is associated with a belonging criterion, the series is run through in order to determine, for each symbol, the encoding model to which it belongs, according to the criteria; then a probability of occurrence of each symbol in the corresponding model is determined; then the series is run through by encoding each symbol successively; and a file is formed from the code thus obtained.

Abstract: Method and apparatus for the digital encoding of a first raw file, the method includes: a first step of capturing the raw file, the raw file being an audio and/or image and/or video file; a second step of encoding the captured raw file into a second file, in a proprietary format (P); then, a third step for re-encoding the second file into a third file in a compatible format (C).

Abstract: A method for reversible coding of an image, including extracting compression information from an image compressed in an original format, at least partly decompressing the compressed image into an intermediate at least partly decompressed image, re-encoding the intermediate image into a re-encoded image, and preferably associating in a same file, the re-encoded image with compression information.

Abstract: Method of differential compression of the values of a matrix, in which the reference cell is chosen in such a way that the difference between the initial value, contained in a cell to be compressed, and the decompressed value of the reference cell is a minimum.

Abstract: A method for compressing a stream by means of a codec (C), provided for assigning to a compressed stream an encoding throughput (Q) measured in bits per second, using a pre-filter (X1) replacing in the header (T1) of the original stream, the restoration frequency (R) with a frequency equal to the product (R×K) of the restoration frequency (R) by a coefficient (K) and then for retransmitting the thereby filtered stream (FX1) to the codec; the post-filter (X2) replacing the restoration frequency (R) into the header (TX2) of a stream (FX2) resulting from the encoding of the pre-filtered stream (FX1) by the codec C.

Abstract: A method for compressing a stream by means of a codec (C), provided for assigning to a compressed stream an encoding throughput (Q) measured in bits per second, using a pre-filter (X1) replacing in the header (T1) of the original stream, the restoration frequency (R) with a frequency equal to the product (R×K) of the restoration frequency (R) by a coefficient (K) and then for retransmitting the thereby filtered stream (FX1) to the codec; the post-filter (X2) replacing the restoration frequency (R) into the header (TX2) of a stream (FX2) resulting from the encoding of the pre-filtered stream (FX1) by the codec C.