Abstract: The present invention relates to a method and device for generating a description file about a video sequence at a server device for a client device, to retrieve a video segment and containing a region of interest. The method comprising for each video segment, determining a time interval during which the detected region of interest is spatially included in a same frame region in the video sequence; and generating a description file comprising spatial information describing the frame region and temporal information describing a duration at least equal to the determined time interval.

Abstract: The invention relates to encapsulating tiled timed media data in a server and providing a timed media data bit-stream from encapsulated tiled timed media in a client device. The tiled timed media data comprises timed samples and each timed sample comprises a plurality of spatial subsamples. After having selected at least one spatial subsample from amongst the plurality of spatial subsamples of one of the timed samples, one tile track comprising the selected spatial subsample and one corresponding spatial subsample of each of the other timed samples is created for each selected spatial subsample. One composite track comprising at least one extractor identifying at least one of the created tile tracks is created. Each created track is independently encapsulated in at least one media segment file.

Abstract: At least one embodiment of a method of encoding a plenoptic image includes: decomposing the plenoptic image into sub-aperture images, encoding at least a part of a first sub-aperture image using a set of encoding parameters, and encoding at least a part of a second sub-aperture image using a restricted number of parameters among the set of encoding parameters. Embodiments make it possible to reduce the encoding complexity and run-time while keeping good encoding performances.

Abstract: A method for compressing a set of images comprising a plenoptic image and at least one refocused image obtained from the plenoptic image for a given focus, by generating a set of data comprising a compressed version of the plenoptic image, some focusing parameter to build a refocused image from this plenoptic image and a compressed residual data to restore the refocused image in its plain quality. Accordingly, the set of images can be compressed in an efficient way, preserving the quality of the shoot using the focus chosen by the photographer.

Abstract: In a method of encoding a video frame to be transmitted to a plurality of clients over a plurality of network connections, a set of parameters is associated with each connection. The method comprises: for each connection, determining a frame size that can be transported over the connection considering the associated set of parameters; and compressing the video frame to a target frame size based on the minimum of the plurality of determined frame sizes. This method advantageously provides an easy and straightforward way for selecting the appropriate parameters that need to be taken into account for controlling the rate of the generated bitstream, particularly when multiple parameters are associated with each connection.

Abstract: A method of processing video data comprising including a link between first encoded image data in a first encoded video stream and second encoded image data in a second encoded video stream, the first and second encoded image data corresponding to a same spatial area of the images of the first and second encoded video streams. Embodiments of the invention provide high resolution display of specific region of interest without a priori knowledge of the position of the region of interest.

Abstract: The invention relates to encapsulating tiled timed media data in a server and providing a timed media data bit-stream from encapsulated tiled timed media in a client device. The tiled timed media data comprises timed samples and each timed sample comprises a plurality of spatial subsamples. After having selected at least one spatial subsample from amongst the plurality of spatial subsamples of one of the timed samples, one tile track comprising the selected spatial subsample and one corresponding spatial subsample of each of the other timed samples is created for each selected spatial subsample. One composite track comprising at least one extractor identifying at least one of the created tile tracks is created. Each created track is independently encapsulated in at least one media segment file.

Abstract: A method of processing video data comprising subdividing a video stream into image portions, encoding the image portions with high resolution in respective encoded video streams and reassembling a selection of encoded video streams in order to display a region of interest with high resolution. Embodiments of the invention provide high resolution display of specific region of interest without a priori knowledge of the position of the region of interest.

Abstract: The invention relates to a method for encoding a plenoptic image comprising a plurality of microlens images, each microlens image formed by an associated microlens, the plenoptic image being associated with acquisition parameters of a plenoptic acquisition system with which the plenoptic image has been obtained, the method comprising decomposing the plenoptic image into a plurality of sub-aperture images, and encoding said plurality of sub-aperture images using one or more encoding parameters, which one or more encoding parameters are determined in dependence upon the acquisition parameters associated with the plenoptic image. The invention also relates to a corresponding device for encoding a plenoptic image.

Abstract: The present invention provides a method for streaming data corresponding to a given video, each frame of the video being divided into n spatial tiles, n being an integer, in order to create n independent video sub-tracks. The method comprises: transmitting, by a server, a description file to a client device, said description file including data about the spatial organization of the n video sub-tracks and at least n URLs respectively designating each video sub-track, selecting by the client device one or more URLs according to one Region Of Interest chosen by the client device or a client device's user, receiving from the client device, by the server, one or more request messages for requesting a resulting number of video sub-tracks, each request message comprising one of the URLs selected by the client device, and transmitting to the client device, by the server, video data corresponding to the requested video sub-tracks, in response to the request messages.

Abstract: The invention concerns a method for decoding a video sequence encoded according to a predictive format, which video sequence includes predicted images containing encoded residual data representing differences between the respective predicted image and a respective reference image in the video sequence. The method of the invention comprises, applying to a current image which contains at least one area which is to be reconstructed, the steps of: obtaining (E605) projected residual data for said at least one area to be reconstructed, from residual data of at least one image predicted from the current image, corresponding to a temporal projection of at least part of the at least one area to be reconstructed onto said at least one image predicted from the current image; and reconstructing (E606) at least part of said at least one area using the projected residual data obtained.

Abstract: A sequence of digital images encoded according to a predictive format is decoded using encoded auxiliary data which is representative of at least part of the sequence of digital images. A current encoded image, received with at least one detected error, is decoded. The decoding includes applying an error concealment decoding on at least part of the current encoded image containing such a detected error to obtain a first decoded image. An item of information representative of reconstruction errors is obtained based upon a reconstruction confidence of the error concealment decoding for at least one pixel of the error-containing part of the current image. The encoded auxiliary data and the first decoded image are processed based upon the item of information representative of reconstruction errors to obtain corrected auxiliary data. The first decoded image is modified to obtain a second decoded image based upon the corrected auxiliary data.

Abstract: The present invention relates to a method and device for generating a description file about a video sequence at a server device for a client device, to retrieve a video segment and containing a region of interest. The method comprising for each video segment, determining a time interval during which the detected region of interest is spatially included in a same frame region in the video sequence; and generating a description file comprising spatial information describing the frame region and temporal information describing a duration at least equal to the determined time interval.

Abstract: A method of processing a stream of coded data before decoding comprises a step of detecting missing or erroneous data in the stream of coded data. It comprises a step of generating a series of data ready for decoding formed from the stream of coded data, and a series of additional data supplying information representing the position of the missing or erroneous data detected.

Abstract: A method for compressing a set of images comprising a plenoptic image and at least one refocused image obtained from the plenoptic image for a given focus, by generating a set of data comprising a compressed version of the plenoptic image, some focusing parameter to build a refocused image from this plenoptic image and a compressed residual data to restore the refocused image in its plain quality. Accordingly, the set of images can be compressed in an efficient way, preserving the quality of the shoot using the focus chosen by the photographer.

Abstract: A method for adapting error protection in a communication network includes: a step of determining periods of time that are homogeneous as regards the distribution law of losses over the network, a step of classifying the homogeneous periods of time into at least two classes, on the basis of information representing losses over the network and/or representing a corresponding level of protection, during these periods of time, a step of determining a probability of alternation between two of said classes, and a step of selecting a protection strategy on the basis of said probability of alternation. A method of detecting transition between two states of a communication network corresponding to different loss rates of sent data includes: a step of determining a probability of transition, and a step of determining the existence of a transition on the basis of said probability.

Abstract: The method of sending at least one item of information relative to a multimedia data stream in a communication network is characterized in that it comprises the following steps carried out on a server device capable of sending the multimedia data stream over the network: obtaining at least one item of information relative to the data stream, said at least one item of information comprising an item of information on a visual quality of the multimedia data stream and an item of information on the bandwidth necessary for sending the stream with that visual quality, and sending said at least one obtained item of information over the communication network to a client device.

Abstract: The invention concerns methods and devices for concealing artefacts induced by transmission errors in a video sequence transmitted over a network between a server and a client making it possible to avoid abrupt resynchronization following a transmission error. When an error is detected, a video stream is created from a first video stream not containing any error and data representing artefacts induced by that error. The influence of the data representing the artefacts diminishes with time such that the created video stream converges towards the video stream not containing any error. The creation of the video stream in which the effects due to a transmission error are progressively removed may be carried out by the server or by the client.

Abstract: This method allows the transmission of coded data representing a sequence of digital images. A predetermined quantity of this data is stored in a buffer before transmission over a communication network. The method comprises a step of determining a subset of data in the buffer to be transcoded, as a function of at least one quantity representing the bandwidth available for the communication network.

Abstract: An encoder extracts motion vectors from a frame I(t?1) preceding the frame I(t) being encoded and processes them to create an estimated motion vector field I(t) for the frame being encoded. A minimised difference between the motion vector field of the frame being encoded and the estimated motion vector field is used to generate transform parameters, which are transmitted to the decoder as auxiliary information along with the usual motion prediction information. The decoder receives the transform parameters. The decoder also creates an estimated motion vector field I(t) for based on a preceding frame I(t?1) and applies the transform parameters to the estimated motion vector field to obtain missing motion vectors. The motion vector field rebuilt using the reconstructed missing motion vectors is used for subsequent error concealment/decoding/displaying.