Abstract:
A method is provided decoding a digital image signal in a decoding terminal that uses a variable-complexity decoding, enabling, for at least one step in the decoding, selection of at least one decoding tool from at least two available decoding tools. The method includes the following steps: identifying from the images control images and intermediate images; applying to each of the control images, for at least one step of the decoding, at least one predetermined decoding tool imposed by the signal; applying to at least one of the intermediate images, for at least one step of the decoding, at least one decoding tool selected by the decoding terminal and not imposed by the signal.
Abstract:
A method is provided for encoding a sequence of images generating a data stream in the form of a structure of embedded data layers of n successive levels each of which corresponds to the predetermined resolution of said images. Said method comprises an encoding stage, which encodes at least one of said layers of an n+1 level by prediction on the basis of said level n layer and encodes each data layer of the level n in the form of a base sub-stream and, optionally, in the form of at least one enhancement sub-stream enabling to obtain at least one version of the enhanced quality of said images. The method also encodes, for at least one data layer of the n level, at least one single sub-stream enabling to reconstruct the version of said images at said level n resolution with a quality higher than said enhanced qualities, wherein said single sub-steam of the level n layer is not used during the prediction encoding of the layers of a level other than the level n.
Abstract:
A method is provided for encoding an image represented by a sequence of symbols. The method includes the following steps: defining subsequences within the sequence; and going through the subsequences applying the following sub-steps for a routine subsequence: determining an adjacent routine encoded group including two previously encoded subsequences, one of which belongs to an adjacent encoded group associated with a subsequence that is separate from the routine subsequence; initializing a routine probability of occurrence of a symbol, taking into account two known probabilities of occurrence of the symbol, relating to two previously encoded subsequences of the adjacent routine encoded group; the consecutive entropic encoding of the symbols, and updating the routine probability of occurrence; and storing the routine probability of occurrence after encoding the last symbol.
Abstract:
A method and apparatus are provided for encapsulating a plurality of data substreams encoded in a bit stream, wherein the encoded data substream is obtained by entropy encoding of a symbol subsequence representing an image or a series of images. The method includes grouping data substreams into substream pairs according to an iterative traversal order predetermined from the plurality of substreams, and on the basis of a pair of the substreams, obtaining a symmetrical pair by reversing a data order making up the second substream of the pair. The obtained pairs are then concatenated within a sequence. The binary stream is created by encapsulating the sequence and information related to a number of substreams and related to the sizes of pairs of symmetrical substreams.
Abstract:
A method and apparatus are provided for coding an image or a sequence of images, generating a data stream including data representative of pixel groups, referred to as blocks, in one of the images. The method includes: grouping blocks in a cluster of blocks according to the proximity of their respective values corresponding to at least one block parameter to be coded; determining a value of the parameter, the value being characteristic of said group of blocks; coding blocks of the cluster, where the values of the blocks for the parameter are coded implicitly by inheritance of the characteristic value or are coded as refinements relative to the characteristic value, and coding a data structure associated with the cluster of blocks, the data structure including data associated with the characteristic value.
Abstract:
A method of coding at least one image comprising the steps of splitting the image into a plurality of blocks, of grouping said blocks into a predetermined number of subsets of blocks, of coding each of said subsets of blocks in parallel, the blocks of a subset considered being coded according to a predetermined sequential order of traversal. The coding step comprises, for a current block of a subset considered, the sub-step of predictive coding of said current block with respect to at least one previously coded and decoded block, and the sub-step of entropy coding of said current block on the basis of at least one probability of appearance of a symbol.
Abstract:
A method is provided for encoding an image sequence, including the step of dividing a reference image into blocks and a prediction step that includes the following steps: determining monitoring vectors associated with a common image and dividing the same into sub-blocks defining a first partition; determining monitoring vectors associated with an image to be compensated and dividing the same into sub-blocks defining a first partition obtaining a common partitioning into basic sub-blocks; determining first and second sets of monitoring vectors for the basic sub-blocks; movement-compensating a sub-block of the image to be compensated towards a sub-block of the common image.
Abstract:
A method is provided decoding a digital image signal in a decoding terminal that uses a variable-complexity decoding, enabling, for at least one step in the decoding, selection of at least one decoding tool from at least two available decoding tools. The method includes the following steps: identifying from the images control images and intermediate images; applying to each of the control images, for at least one step of the decoding, at least one predetermined decoding tool imposed by the signal; applying to at least one of the intermediate images, for at least one step of the decoding, at least one decoding tool selected by the decoding terminal and not imposed by the signal.
Abstract:
A method and apparatus are provided for decoding a signal representative of an image sequence. The method includes extracting motion tubes from the signal, each of the tubes being defined by at least the following information cues: a block of reference pixels comprising reference texture information cues; start-of-tube and end-of-tube instants; and transition information cues. The method further includes processing the transition information cues and combining the information cues associated with the current blocks of at least two of the tubes overlapping in an overlap zone of the current image.
Abstract:
A method is provided for encoding a sequence of images generating a data stream in the form of a structure of embedded data layers of n successive levels each of which corresponds to the predetermined resolution of said images. Said method comprises an encoding stage, which encodes at least one of said layers of an n+1 level by prediction on the basis of said level n layer and encodes each data layer of the level n in the form of a base sub-stream and, optionally, in the form of at least one enhancement sub-stream enabling to obtain at least one version of the enhanced quality of said images. The method also encodes, for at least one data layer of the n level, at least one single sub-stream enabling to reconstruct the version of said images at said level n resolution with a quality higher than said enhanced qualities, wherein said single sub-steam of the level n layer is not used during the prediction encoding of the layers of a level other than the level n.