France Telecom

Orange

Nathalie Cammas

Isabelle Amonou

Stéphane Pateux

Sylvain Kervadec

Stephane Pateux

Matthieu Moinard

Stéphanie Relier

Benjamin Le Guen

Nathalie Laurent-Chatenet

Stéphane Kervadec

A method and apparatus for encoding a sequence of images by predicting at least one current image by forward motion compensation from at least one reference image. Prediction implements, for at least one current block of the current image: forward projection of a block of the reference image on the current image, delivering a projected block at least partially overlapping the current block; partitioning the current block delivering a sub-block at least partially overlapped by at least one projected block; and at least one iteration of the following steps for at least one overlapped sub-block: checking that the overlapped sub-block complies with a predetermined allotting criterion; with a positive check, allotting, to the overlapped sub-block, one of the projected motion vectors; and with a negative check, and so long as a predetermined minimum size is not reached for the overlapped sub-block: partitioning of the overlapped sub-block.

Methods and devices for encoding and decoding an image sequence implementing a prediction by forward motion compensation, corresponding stream and computer program

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.

Data substream de-encapsulation method for plural symmetrical substreams and corresponding computer programs

A method and apparatus are provided for encoding an image sequence. The method includes the following steps, for at least one group of blocks of an image: determining, for each block, at least one parameter characteristic of said block; forming at least one cluster including the blocks having at least one similar characteristic parameter; encoding the blocks of said cluster, the similar characteristic parameter(s) associated with said cluster being encoded only once; encoding the blocks that do not belong to any cluster, the characteristic parameter(s) associated with each of said blocks not being encoded; generating a data stream; and inserting into said stream, at least one piece of information on the partitioning of the group(s), in order to identify the outer block(s) within a group.

Method for encoding and decoding images, encoding and decoding devices, corresponding data streams and computer program

A method is provided for coding an image sequence, including splitting a current image into blocks of standard size, termed macroblocks. For at least one current macroblock of the current image, the method further includes: constructing at least one block of greater size than the current macroblock, termed a large block, which includes the current macroblock and at least one neighbor macroblock in the current image, taking account of characteristics of the current image; coding the large block, delivering base coding information, making it possible to reconstruct a base layer of said current image, and for at least one large block, determining enhancement information associated with at least one macroblock present in the large block.

Method and device for coding an image sequence implementing blocks of different size, signal, data medium, decoding method and device, and computer programs corresponding thereto

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.

Methods for encoding and decoding images, corresponding encoding and decoding devices and computer programs

A method and apparatus are provided for coding a signal from images, the images being split into sub-blocks of pixels. The method includes grouping at least two sub-blocks into at least one block of larger size, when the sub-blocks comply with at least one predetermined grouping criterion. A prediction is performed by applying at least one mode of motion prediction using at least two distinct motion prediction vectors, for at least one block of larger size, the motion prediction vectors being associated respectively with sub-sets of the block of larger size, comprising at least one of the sub-blocks of the block of larger size. The sub-sets are predefined and distinct.

Method of coding and decoding images, corresponding device for coding and decoding and computer program

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.

Methods for encoding and decoding sequence implementing a motion compensation, corresponding encoding and decoding devices, signal and computer programs

A method is provided for encoding at least one image, divided into macroblocks, one macroblock including a set of blocks de pixels. The method includes, for at least one current macroblock of a current image, at least two iterations of the following steps: allocation of a priority level for encoding to at least one pixel of the current macroblock, selection of a pixel with the highest priority level called the priority pixel, prediction of a set of pixels including the priority pixel and a step of encoding a remainder from prediction for a region made up of predicted pixels of the macroblock, called the predicted region, the encoding step being used as and when the predicted region meets a predetermined encoding criterion.

Method and device for encoding an image using a prediction mask decoding method and device and corresponding signals and computer programs

A method is provided for predicting an image by compensation during forward movement from at least one reference image. For at least one block of a reference image, referred to as a reference block, the prediction method includes the following steps: determining at least one piece of movement information, representing a movement between said reference block and a matching block in the image to be predicted; determining at least one enlarged block, including the reference block and at least one point of a block adjacent to said reference block in the reference image; and determining a prediction value for at least one point of the image to be predicted from the at least one enlarged block and from the movement information determined for the reference block.

Prediction of an image by compensation during forward movement

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.

Encoding and decoding an image or image sequence divided into pixel blocks

A method and apparatus are provided for coding a sequence of images. The method includes a step of coding at least one block of a current image of the sequence, implementing a prediction associating the block with at least one corresponding block in a reference image. The prediction includes the following steps, for at least one given block of the current image or of the reference image: determination of a plurality of control vectors for the block; at least one splitting of the block into sub-blocks; determination of a plurality of control vectors for the sub-blocks; and determination of a prediction value for at least one point of the current image. Moreover, the method includes a step of inserting, into a signal representative of the sequence, information regarding reconstruction of the control vectors for the given block.

Method and device for encoding a sequence of images implementing a temporal prediction, corresponding signal, data storage medium, method and decoding device and computer program products

The invention concerns a method which consists in analyzing a field of motion of images, estimated by using a first mesh, to detect a faulty area in the first mesh, and in locating a rupture line in said area; then generating a second mesh including a faultless part consisting of meshes of the first mesh outside the faulty area and two sub-meshes which overlap in a region including the rupture line. Each of the two sub-meshes includes respective meshes delimited by nodes including nodes shared with the faultless part, located at the boundary of the faulty area, and additional nodes not belonging to the faultless part, the rupture line being located between the respective nodes of the two sub-meshes shared with the faultless part. Said second mesh is used to finally estimate the field of motion in the group of images concerned.

Method of estimating motion in sequences of moving images using deformable meshes, video coder and decoder implementing the method

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.

Methods and devices for coding and decoding an image sequence represented with the aid of motion tubes, corresponding computer program products and signal

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Sens de Bretagne, France

Nathalie Cammas