Abstract:
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.
Abstract:
Techniques are provided for encoding and decoding image data. The techniques implement a prediction of data of a current block based on at least one already encoded block or reference block, wherein said prediction step takes into account a set of encoded blocks adjacent to said current block and including blocks that have not yet been considered according to said writing path order. Encoding includes the steps of: generating a dependence tree associating a current block with at least one reference block from which the predicted block associated with the current block has been predetermined; and inserting information representative of said dependence tree into said set of data associated with each block.
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:
Method of coding an image or a sequence of images generating a flow of data in the form of groups of blocks, at least one group of blocks containing image blocks having a resolution and a quality level of identical quantification, characterized in that said method comprises at least the following steps for the at least one group of blocks, of a) a first coding so that each block of the at least one group of blocks has at least one associated parameter that is given a first value, and b) a second coding for giving said associated parameter for at least one block of said at least one group of blocks a second value, so that for said at least one bloc, the first and second values given for said parameter can be combined during decoding in order to provide a value assigned to said parameter.
Abstract:
Data associated with transmitted information over a communication network are transmitted. The data are divided into data groups. An information item representative of the importance of the data of the data group is associated with each data group. A transmission cycle for the data groups is determined. Each data group is inserted into the determined transmission cycle a number of times depending on the importance of the data of the data group.
Abstract:
A video image sequence including coefficients of frequency sub-bands with different spatial resolutions is coded. A data stream including at least one restitution level (Niv N−2, Niv N−1, Niv N) is formed. The restitution levels have coefficients of frequency sub-bands whose spatial resolution equals a spatial resolution of the restitution level. There are inserted, in at least one restitution level, coefficients of frequency sub-bands with a spatial resolution higher than the spatial resolution or resolutions of the restitution level.
Abstract:
In order to code a digital signal, a simplified version of the digital signal is determined, containing only some of the information contained in the digital signal. The simplified version is coded by means of a predetermined single coding technique. This simplified version is subtracted from the digital signal, so as to obtain a residual signal. From each block of the simplified version, there is selected, for each corresponding block of the residual signal, a coding technique amongst a predetermined number M of coding techniques Ci, where i is an integer between 1 and M. Each block of the residual signal is coded by means of the previously selected coding technique.
Abstract:
In order to code a digital signal, it is decomposed (20) into several subsignals; each subsignal is coded (38) by means of a coding technique taken from amongst M coding techniques Ci; and the stream of coded bits thus produced is entered (40) in a first part of a file intended to receive the coded digital signal. Then the application, successively to each coded subsignal, of each decoding technique Di associated with the coding technique Ci is simulated (48); and if and only if at least two different decoding techniques are acceptable, within the meaning of a predetermined likelihood criterion, for decoding the same coded subsignal, there is entered (52) in a second part of the file information making it possible to select, during decoding, the decoding technique associated with the coding technique used for coding this subsignal.
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.