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: 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 is disclosed for compressing a sequence of initial digital values into a compressed sequence of compressed values, intending to restore these values into a decompressed sequence of decompressed values. For a first initial value of the sequence, the compressed value of the first initial value is equal to the first initial value and the decompressed value of the compressed value of the first initial value is equal to the first initial value.

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: 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 processing a digital file of the images, video and/or audio type which comprises a phase for putting into line per color layer and/or per audio channel, digital data of any audio, image and video file, a compression phase using algorithm in which each compressed value VCn of position N is obtained by subtracting from the value Vn of same position N of the original file, a predetermined number of successive compressed values (VCn-1, VCn-2, . . . ) calculated previously, and a restoration phase using an algorithm in which each restored value VDn of position N is obtained by adding to the value VCn, of the same position of the compressed file, a predetermined number of successive compressed values (VCn-1, VCn-2, . . . ).

Abstract: The invention concerns a method comprising a coding step consisting in replacing the original values of the file with coding values of reduced brightness, a common coding value being attributed to a group of original values, a step of restitution consisting in setting correspondence values between the coding value and the restored value, selected from one of the values of the corresponding group, an insertion step consisting in modifying the successive redundant restored values so as to produce shades and a step which consists in reading the values resulting from the insertion step.

Abstract: A method for processing a digital file of the images, video and/or audio type which comprises a phase for putting into line per color layer and/or per audio channel, digital data of any audio, image and video file, a compression phase using algorithm in which each compressed value VCn of position N is obtained by subtracting from the value Vn of same position N of the original file, a predetermined number of successive compressed values (VCn-1, VCn-2, . . . ) calculated previously, and a restoration phase using an algorithm in which each restored value VDn of position N is obtained by adding to the value VCn, of the same position of the compressed file, a predetermined number of successive compressed values (VCn-1, VCn-2, . . . ).

Abstract: The inventive method makes it possible to reduce the size of a digital audio, image and/or video file in such a way that a reduced number of representative data needed for reformatting a file is transmitted to a receiving entity encoder. Said method consists in assigning references of at least one file component value to another value of the same component or in integrating at least one reference of the value group of the same component or another component into a component value group.