Abstract: Encoding a digital image divided into a plurality of blocks of pixels processed in a defined order, including the following steps, implemented for a current block, with preset sizes: predicting values of the current block from at least one block previously processed; calculating a residual block by subtracting the predicted values from the original values of the current block; obtaining a residual block by applying a transform to pixels of the residual block, said transformed residual block comprising coefficients; encoding the transformed residual block; calculating at least one characteristic representative of at least one transformed residual coefficient of the current block; determining initial identification data representative of a sub-list of at least one transform associated with said at least one calculated characteristic; and verifying that the transform applied to the current block is part of the sub-list identified by the initial data.

Abstract: Encoding a digital image divided into a plurality of blocks of pixels processed in a defined order, including the following steps, implemented for a current block, with preset sizes: predicting values of the current block from at least one block previously processed; calculating a residual block by subtracting the predicted values from the original values of the current block; obtaining a residual block by applying a transform to pixels of the residual block, said transformed residual block comprising coefficients; encoding the transformed residual block; calculating at least one characteristic representative of at least one transformed residual coefficient of the current block; determining initial identification data representative of a sub-list of at least one transform associated with said at least one calculated characteristic; and verifying that the transform applied to the current block is part of the sub-list identified by the initial data.

Abstract: A method of coding at least one image sliced into blocks. The method implements, for a current block to be coded: predicting the current block in accordance with a prediction mode selected from among predetermined prediction modes, Intra and Inter, the selected mode of prediction being Intra; calculating a residual data block representative of a difference between a predictor block obtained on completion of the prediction and the current block; applying a transform operation to the data of the residual block, the transform operation belonging to a set of transform operations previously stored in association with the selected mode of Intra prediction; and coding the data obtained from the transform operation. The number of transform operations contained in the set associated with the selected Intra mode is different from the number of transform operations contained in a set of transform operations stored in association with the mode of Inter prediction.

Abstract: A method and device for coding at least one current image parameter, wherein, in relation to a zone of a current image, the method implements the following: as a function of the value of at least one parameter of an image zone which precedes that zone of the current image, selecting a scheme for coding the at least one current image parameter, from among at least two predetermined coding schemes, and coding the value of the at least one current image parameter with the aid of the selected coding scheme.

Abstract: A method for decoding a current block of a digital image. The method includes: decoding coefficients of the current block; and transforming the current block into a decoded block, by implementing a first sub step to produce an intermediate block, that applies to the column and row vectors of the current block, and a second substep to produce a block of pixels that applies to the row and column vectors of the intermediate block, resulting from the first substep; and rebuilding the image from the decoded block. At least one of the first and second substeps includes, for an input row or column vector: forming a first subvector of size K<N or N respectively from adjacent elements of the input vector; transforming the first subvector into a first transformed subvector by applying a partial subtransform of size K×K; and building the transformed vector by inserting the first transformed subvector.

Abstract: A method for encoding at least one image split into blocks. The method includes, for a current block to be encoded from the image, at least one modification of two data points in the block via an operation of linear combinations operating on the two data points, at the end of which a modified block is obtained, application of a separable transform operation to the data points in the modified block, and encoding the data points obtained after application of the separable transform operation.

Abstract: A method for decoding a data signal representative of at least one image cut into blocks. The method includes, for a current block to be decoded: transforming a residual data block obtained from the data signal; determining a permutation-transformation pair including a transformation mathematical operation and a permutation mathematical operation, the transformation mathematical operation and the permutation mathematical operation belonging to respectively a plurality of permutation operations and a plurality of transformation operations; applying the determined transformation mathematical operation to the data of the residual data block to produce transformed data; applying the determined permutation mathematical operation to the transformed data to produce permuted data, the determined permutation mathematical operation being an operation of transposing the transformed data; and using the permuted data to reconstruct the current block by a predictive decoding.

Abstract: A method of coding at least one image sliced into blocks. The method implements, for a current block to be coded: predicting the current block in accordance with a prediction mode selected from among predetermined prediction modes, Intra and Inter, the selected mode of prediction being Intra; calculating a residual data block representative of a difference between a predictor block obtained on completion of the prediction and the current block; applying a transform operation to the data of the residual block, the transform operation belonging to a set of transform operations previously stored in association with the selected mode of Intra prediction; and coding the data obtained from the transform operation. The number of transform operations contained in the set associated with the selected Intra mode is different from the number of transform operations contained in a set of transform operations stored in association with the mode of Inter prediction.

Abstract: A method is provided for encoding at least one image cut into blocks. The method implements, for a current block to be encoded, the acts of: predicting the current block with the aid of at least one predictor block, determining a residual data block representative of the difference between the predictor block and the current block, selecting, according to a predetermined criterion, a pair of mathematical operations including a permutation operation and a transformation operation from among a plurality of permutation operations, and a plurality of transformation operations, applying the permutation operation of said selected pair to the data of the determined residual block, applying the transformation operation of said selected pair to the permuted data, and encoding the data from said applied transformation operation.

Abstract: A method of coding at least one image sliced into blocks. The method implements, for a current block to be coded of the image: predicting the current block in accordance with a prediction mode selected from among a plurality of predetermined prediction modes, calculating a residual data block representative of a difference between a predictor block obtained on completion of the prediction and the current block, applying a transform operation to the data of the residual block, the transform operation belonging to a set of transform operations previously stored in association with a selected prediction mode, and coding the data obtained from the transform operation. The number of transform operations contained in the set associated with the selected mode is different from the number of transform operations contained in a set of transform operations stored in association with at least one other predetermined prediction mode of the plurality.

Abstract: A method is provided for encoding at least one image cut into blocks. The method includes, for a current block having K pixels to be encoded, wherein K>1, acts including: predicting the current block using at least one predictive block having K pixels; then determining a residual block having K pixels and representing the difference between the predictive block and the common block. A set of Mi data is determined from a pixel block group containing a number Mi of blocks having K pixels and each representing a predetermined texture, wherein 1<Mi<K, by calculating the pixel-by-pixel product of the residual block determined by each of the Mi blocks of K pixels representing a predetermined texture, and encoding the Mi data from the determined data set.

Abstract: A method and device for coding at least one current image parameter, wherein, in relation to a zone of a current image, the method implements the following: as a function of the value of at least one parameter of an image zone which precedes that zone of the current image, selecting a scheme for coding the at least one current image parameter, from among at least two predetermined coding schemes, and coding the value of the at least one current image parameter with the aid of the selected coding scheme.

Abstract: A method and device are provided for coding or decoding a digital audio signal by transform using analysis or synthesis weighting windows applied to sample frames. The method includes an irregular sampling of an initial window provided for a transform of given initial size N, to apply a secondary transform of size M different from N.

Abstract: A method for decoding a current block of a digital image. The method includes: decoding coefficients of the current block; and transforming the current block into a decoded block, by implementing a first sub step to produce an intermediate block, that applies to the column and row vectors of the current block, and a second substep to produce a block of pixels that applies to the row and column vectors of the intermediate block, resulting from the first substep; and rebuilding the image from the decoded block. At least one of the first and second substeps includes, for an input row or column vector: forming a first subvector of size K<N or N respectively from adjacent elements of the input vector; transforming the first subvector into a first transformed subvector by applying a partial subtransform of size K×K; and building the transformed vector by inserting the first transformed subvector.

Abstract: A method of coding at least one image sliced into blocks. The method implements, for a current block to be coded of the image: predicting the current block in accordance with a prediction mode selected from among a plurality of predetermined prediction modes, calculating a residual data block representative of a difference between a predictor block obtained on completion of the prediction and the current block, applying a transform operation to the data of the residual block, the transform operation belonging to a set of transform operations previously stored in association with a selected prediction mode, and coding the data obtained from the transform operation. The number of transform operations contained in the set associated with the selected mode is different from the number of transform operations contained in a set of transform operations stored in association with at least one other predetermined prediction mode of the plurality.

Abstract: A method for encoding at least one image split into blocks. The method includes, for a current block to be encoded from the image, at least one modification of two data points in the block via an operation of linear combinations operating on the two data points, at the end of which a modified block is obtained, application of a separable transform operation to the data points in the modified block, and encoding the data points obtained after application of the separable transform operation.

Abstract: Encoding a digital image divided into a plurality of blocks of pixels processed in a defined order, including the following steps, implemented for a current block, with preset sizes: predicting values of the current block from at least one block previously processed; calculating a residual block by subtracting the predicted values from the original values of the current block; obtaining a residual block by applying a transform to pixels of the residual block, said transformed residual block comprising coefficients; encoding the transformed residual block; calculating at least one characteristic representative of at least one transformed residual coefficient of the current block; determining initial identification data representative of a sub-list of at least one transform associated with said at least one calculated characteristic; and verifying that the transform applied to the current block is part of the sub-list identified by the initial data.

Abstract: An encoding method encodes a digital image that is divided into a plurality of blocks of pixels processed in a defined order. The method includes: transforming the current block into a transformed block with coefficients, by implementing two successive transformation sub-steps, one to the current block and the other to an intermediate block, resulting from the first sub-step; and quantizing and encoding the coefficients of the transformed block. The transforming step further comprises, a preliminary sub-step of forming at least one first and one second distinct vector, in the block to be transformed, each vector comprising the pixels, respectively the coefficients of a sequence of pixels, respectively adjacent coefficients of the block to be transformed, of length equal to one of the sizes of the block to be transformed. The transformation sub-step also includes applying a first transform to the first vector and a second transform to the second vector.

Abstract: A method for processing a signal in the form of consecutive sample blocks, the method comprising filtering in a transformed domain of sub-bands, and particularly equalization processing, applied to a current block in the transformed domain, and filtering-adjustment processing that is applied in the transformed domain to at least one block adjacent to the current block.

Abstract: A method is provided for encoding at least one image cut into blocks. The method includes, for a current block having K pixels to be encoded, wherein K>1, acts including: predicting the current block using at least one predictive block having K pixels; then determining a residual block having K pixels and representing the difference between the predictive block and the common block. A set of Mi data is determined from a pixel block group containing a number Mi of blocks having K pixels and each representing a predetermined texture, wherein 1<Mi<K, by calculating the pixel-by-pixel product of the residual block determined by each of the Mi blocks of K pixels representing a predetermined texture, and encoding the Mi data from the determined data set.