Abstract: A method and a device for generating a data stream representative of a volumetric video generated from a sequence of multi-plane images are disclosed. A quantization law depending on an angular resolution used to generate patches from the multi-plane images is set up. For each intra-periods of the frame sequence, patches are generated for a given angular resolution. If generated patches do not fit in atlas images of a target size, the angular resolution is decreased and patches are generated again according to this new angular resolution.

Abstract: A sequence of point clouds is encoded as a video by an encoder and transmitted to a decoder which retrieves the sequence of point clouds. Visible points of a point cloud are iteratively projected on projection maps according to at least two centers of projection, to determine a patch data item lists. One of the centers of projection is selected and corresponding image patches are generated and packed into a picture. Pictures and associated patch data item list are encoded in a stream. The decoding method decodes pictures and associated patch data item lists. Pixels of image patches comprised in pictures are un-projected according to data stored in associated patches. The methods have the advantage of encoding every point of point clouds in a manner avoiding artifacts and allowing decoding at video frame rate.

Abstract: Methods, apparatuses and streams are disclosed for transmitting tiled volumetric video and, at the receiver, for generating an atlas image compatible with a legacy decoder. At the server side, viewport information is obtained and a first list of central tiles and a second list of border tiles are selected. A central tile is a part of an image obtained by projecting the 3D scene onto an image plane according to a central point of view. A border tile is an image comprising dis-occluding patches. Sizes and shapes of border tiles are function of size and shape of central tiles. At the client side, tiles are arranged according to a layout selected in a set of layouts according to the number, sizes and shapes of border tiles. FIG. 8.

Abstract: Methods and device for encoding/decoding data representative of depth of a 3D scene. The depth data are quantized in a range of quantized depth values larger than a range of encoding values allowed by a determined encoding bit depth. For blocks of pixels comprising the depth data, a first set of candidate quantization parameters is determined. A second set of quantization parameters is determined as a subset of the union of the first sets. The second set comprising candidate quantization parameters common to a plurality of blocks. One or more quantization parameters of the second set being associated with each block of pixels of the picture. The second set of quantization parameters is encoded, and the quantized depth values are encoded according to the quantization parameters.

Abstract: Methods and device for encoding/decoding data representative of a 3D scene.

Abstract: A method for presenting an image on a display device (100) includes modifying the image by applying a geometric transformation to the image so that an area of the image on the display device is presented to a viewer with higher density of pixels than that in the rest of the image (S18).

Abstract: Methods and devices are provided for encoding, transmitting and decoding 3DoF+ volumetric video. At the encoding stage one input view (among all the input ones) is selected to convey the viewport dependent light effect and its id is transmitted to the decoder as an extra metadata. On the decoder side, when patches coming from this selected view are available for the rendering of the viewport, they are preferentially used regarding the other candidates whatever the view to synthesize position.

Abstract: Methods, devices and stream for encoding, decoding and transmitting a multi-views frame are disclosed. In a multi-views frame some of the views are more trustable than others. The multi-views frame is encoded in a data stream in association with metadata that comprise, for at least one of the views, a parameter indicating a degree of confidence in the information carried by this view. This information is used at the decoding side to determine the contribution of the view when synthetizing pixels of a viewport frame for a given point of view in the 3D space.

Abstract: The present disclosure relates to a method for embedding key information in an image, the method comprising reserving a range of DMZ values, in a predetermined range of 2N values used for storing useful data in the image, the reserved range being used for storing a key information associated with at least one coordinates in the image, with N>0 and DMZ<<2N.

Abstract: Methods and devices are provided to encode and decode a data stream carrying data representative of a three-dimensional scene, the data stream comprising color pictures packed in a color image; depth pictures packed in a depth image; and a set of patch data items comprising de-projection data; data for retrieving a color picture in the color image and geometry data. Two types of geometry data are possible. The first type of data describes how to retrieve a depth picture in the depth image. The second type of data comprises an identifier of a 3D mesh. Vertex coordinates and faces of this mesh are used to retrieve the location of points in the de-projected scene.

Abstract: Encoding/decoding data representative of a 3D representation of a scene according to a range of points of view can involve generating a depth map associated with a part of the 3D representation according to a parameter representative of a two-dimensional parameterization associated with the part and data associated with a point included in the part, wherein the two-dimensional parameterization can be responsive to geometric information associated with the point and to pose information associated with the range of points of view. A texture map associated with the part can be generated according to the parameter and data associated with the point. First information representative of point density of points in a part of the part can be obtained. The depth map, texture map, parameter, and first information can be included in respective syntax elements of a bitstream.

Abstract: A sequence of three-dimension scenes is encoded as a video by an encoder and transmitted to a decoder which retrieves the sequence of 3D scenes. Points of a 3D scene visible from a determined point of view are encoded as a color image in a first track of the stream in order to be decodable independently from other tracks of the stream. The color image is compatible with a three degrees of freedom rendering. Depth information and depth and color of residual points of the scene are encoded in separate tracks of the stream and are decoded only in case the decoder is configured to decode the scene for a volumetric rendering.

Abstract: Methods and device for encoding/decoding data representative of a 3D scene.

Abstract: A sequence of point clouds is encoded as a video by an encoder and transmitted to a decoder which retrieves the sequence of point clouds. Visible points of a point cloud are iteratively projected on projection maps according to at least two centers of projection, to determine a patch data item lists. One of the centers of projection is selected and corresponding image patches are generated and packed into a picture. Pictures and associated patch data item list are encoded in a stream. The decoding method decodes pictures and associated patch data item lists. Pixels of image patches comprised in pictures are un-projected according to data stored in associated patches. The methods have the advantage of encoding every point of point clouds in a manner avoiding artifacts and allowing decoding at video frame rate.

Abstract: Methods and device for encoding/decoding data representative of depth of a 3D scene. The depth data are quantized in a range of quantized depth values larger than a range of encoding values allowed by a determined encoding bit depth. For blocks of pixels comprising the depth data, a first set of candidate quantization parameters is determined. A second set of quantization parameters is determined as a subset of the union of the first sets. The second set comprising candidate quantization parameters common to a plurality of blocks. One or more quantization parameters of the second set being associated with each block of pixels of the picture. The second set of quantization parameters is encoded, and the quantized depth values are encoded according to the quantization parameters.

Abstract: Methods and device for encoding/decoding data representative of a 3D scene. First data representative of texture of the 3D scene visible from a first viewpoint is encoded into first tracks. The first data is arranged in first tiles of a first frame. Second data representative of depth associated with points of the 3D scene is encoded into second tracks. The second data is arranged in second tiles of a second frame, the total number of second tiles being greater than the total number of first tiles. Instructions to extract at least a part of the first data and second data from at least a part of the at least a first track and at least a second track are further encoded into one or more third tracks.

Abstract: The present disclosure relates to a method for embedding key information in an image, the method comprising reserving a range of DMZ values, in a predetermined range of 2N values used for storing useful data in the image, the reserved range being used for storing a key information associated with at least one coordinates in the image, with N>0 and DMZ<<2N.

Abstract: A sequence of point clouds is encoded as a video by an encoder and transmitted to a decoder which retrieves the sequence of point clouds. Visible points of a point cloud are iteratively projected on projection maps according to at least two centers of projection, to determine a patch data item lists. One of the centers of projection is selected and corresponding image patches are generated and packed into a picture. Pictures and associated patch data item list are encoded in a stream. The decoding method decodes pictures and associated patch data item lists. Pixels of image patches comprised in pictures are un-projected according to data stored in associated patches. The methods have the advantage of encoding every point of point clouds in a manner avoiding artifacts and allowing decoding at video frame rate.

Abstract: The present disclosure relates to method for embedding key information in an image, the method comprising reserving a range of DMZ values, in a predetermined range of 2N values used for storing useful data in the image, the reserved range being used for storing a key information associated with at least one coordinates in the image, with N>0 and DMZ<<2N.

Abstract: Methods and device for encoding/decoding data representative of a 3D scene. First data representative of texture of the 3D scene visible from a first viewpoint is encoded into first tracks. The first data is arranged in first tiles of a first frame. Second data representative of depth associated with points of the 3D scene is encoded into second tracks. The second data is arranged in second tiles of a second frame, the total number of second tiles being greater than the total number of first tiles. Instructions to extract at least a part of the first data and second data from at least a part of the at least a first track and at least a second track are further encoded into one or more third tracks.