Abstract:
The methods for transmission of sequences or frames of data provide for retransmitting, with a central device (21), frames of data which reach it, to destination devices, by transmission of downlink frames when the destination device is a peripheral device (24), each downlink frame having systematically a service message activating a protocol controlling access to the transmission medium shared by the central device (21) and the peripheral devices (24), and possibly a frame of data. The central device (21) and at least one peripheral device (24) form a system which is particularly well suited to a local area network, notably with a wireless transmission medium.
Abstract:
A method and device are provided for encoding at least one image broken up into blocks. The method includes, for at least one current block, transforming the current block from the spatial domain into a transformed domain, outputting a transformed block including of a set of coefficients representative of the current block, referred to as original coefficients. The method further includes selecting a subset of original coefficients from the set and, for at least one original coefficient of the subset, the following steps: estimating the original coefficient, outputting an estimated coefficient in the transformed domain; determining a residual of a coefficient by comparing the original coefficient and the estimated coefficient; and encoding the residual of a coefficient.
Abstract:
A method for coding a sequence of video images comprising a cutting into zones of at least one current image of the sequence, characterized in that, for the coding of at least one target zone of said at least one current image, it comprises the steps of: determination (E2) of a set of candidate zones in previously coded and then decoded parts of images of the sequence, minimizing a prediction error calculated over the neighborhood of the target zone, formation (E3) of a set of groups of candidate zones in said set of candidate zones, as a function of a criterion of similarity between the candidate zones, identification (E6) of a best group in said set of groups, minimizing a reconstruction error with respect to the target zone, determination (E6) of an indication (n) representative of said identified best group; and coding (E7) of said indication (n).
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 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 and apparatus are provided for encoding an image sequence. The method includes the following steps for at least one current image of the sequence, namely: construction of an epitome representative of the current image, from a set of at least two images from the sequence; and inter-image prediction of the current image from the epitome.
Abstract:
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.
Abstract:
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.
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.