Abstract: Methods, devices and stream for encoding, decoding and transmitting a multi-views frame are disclosed. A non-pruned MVD frame is obtained and an acyclic graph representing pruning precedence relations between views is determined. The MVD is pruned by using these precedence relations. The pruned MVD and data representative of the graph are encoded in the data stream. At the decoding, the contribution of each view for a pixel of a viewport frame to generate is determined as a function of the decoded pruning graph.

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: Methods and devices for encoding and decoding a data stream representative of a 3D volumetric scene comprising haptic features associated with objects of the 3D scene are disclosed. At the encoding, haptic features are associated with objects of the scene, for instance as haptic maps. Haptic components are stored in points of the 3D scene as color may be. These components are projected onto patch pictures which are packed in atlas images. At the decoding, haptic components are un-projected onto reconstructed points as color may be according to the depth component of pixels of the decoded atlases.

Abstract: A method and a device provide for transmitting information representing a viewpoint in a 3D scene represented with a set of volumetric video contents; receiving a first volumetric video content of the set, the first volumetric video content being according to a range of points of view comprising the viewpoint, the first volumetric video content being represented with a set of first patches, each of which corresponds to a 2D parametrization of a first group of points in a 3D part of the 3D scene associated with the first volumetric video content, and at least one first patch refers to an area of a second patch corresponding to a 2D parametrization of a second group of points in another 3D part of the 3D scene associated with a second volumetric video content of the set of volumetric video contents.

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: At least one embodiment relates to a method and apparatus for encoding a volumetric video representing a scene, said encoding being based on patches representing the color and depth of a 2D projection of subparts of the scene, wherein a first patch is packed in a second patch for a given time interval lower than or equal to a time period along which the second patch is defined when said first patch can be packed in said second patch over said time interval. Decoding method and apparatus are also provided.

Abstract: Generating an image from a source image can involve encoding a projection of a part of a three-dimensional scene. Pixels of a source image comprise a depth and a color attribute. Pixels of a source image are de-projected as colored point cloud. A de-projected point in a 3D space has the color attribute of the pixel that it has been de-projected from. Also, a score is attributed to the generated point according to a local depth gradient and/or a local color gradient of the pixel it comes from, the lower the gradient, the higher the score. The generated point cloud is captured by a virtual camera for rendering on a display device. The point cloud is projected onto the viewport image by blending color of points projected on a same pixel, the blending being weighted by the scores of these points.

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 method and a device are disclosed to encode volumetric video in a patch-based atlas format in intra-periods of varying length. A first atlas layout is built for a first sequence of 3D scenes. The number of 3D scenes in the sequence is chosen to fit the size of a GoP of the codec. A second sequence is iteratively set up by appending the next 3D scene of the sequence to encode while the number of patches of the layout built for this iterative second sequence is lower than or equal to the number of patches of the first layout. When iterations end, one of the layouts is selected to generate every atlas of the group. In such a way, size of metadata is decreased and compression is enhanced.

Abstract: Methods, devices and stream are disclosed for encoding, transporting and decoding a 3D scene prepared to be viewed from the inside of a viewing zone. A central view comprising texture and depth information is encoded by projected points of the 3D scene visible from a central point of view onto an image plane. Patches are generated to encode small parts of the 3D scene not visible from the central point of view. At the rendering, a viewport image is generated for the current point of view. Holes, that is dis-occluded areas, of the viewport are filled using a patch based inpainting algorithm adapted to take the patches, warped according to the rotation and translation between virtual camera used for capturing the patch and the current virtual camera.

Abstract: Methods, device and data stream format are disclosed in the present document for the encoding, the formatting and the decoding of depth information representative of a 3D scene. Compression and decompression of quantized values by a video codec leads to a value error. This error on values is particularly sensitive for depth encoding. The present invention proposes to encode and decode depth with a quantization function that minimize an angle error when a value error on quantized depth creates a location delta between the projected point and the de-projected point. The inverse of such a quantization function has to be encoded in metadata associated with the 3D scene, for example as a LUT, to be retrieved at the decoding, as such functions are not tractable.

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: Methods and devices are provided to encode points of a sphere onto an image by projecting them as a function of an isotropic region guided mapping operator and/or to decode pixels of an image onto a sphere by de-projected them according to the same parametrized mapping operator. A region of interest is determined on the sphere and the angular resolution of pixels of the image is modulated as a function of their distance to the reference pixel corresponding to the center of the region of interest. Chosen angular resolutions and size of the region of interest are associated with the image and encoded in a stream.

Abstract: A position and an orientation of a user in a virtual 3D scene is determined (22), an action is executed (24) in the virtual 3D scene for the user in function of the position and orientation of the user with respect to a given place, and a result of the action is outputted (25). For at least one event in the scene consisting in a presence of at least one determined virtual content, metadata linking the event(s) and at least one place of the event(s) are obtained (21). A given event and the given place linked by those metadata are determined (241), in function of the above position and orientation and of a relationship between that event and a user profile of the user. The action regarding the determined given event and place is executed.

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.