Abstract: Methods, devices and video data encoding a volumetric 3D scene are disclosed. The user is allowed to modify values of rendering effects for some objects of the 3D scene in ranges provided by the content creator or the broadcaster. Metadata describing the possibilities of modifications, the concerned objects and authorized ranges of values are associated with the payload content. On the decoding side, according to these metadata an interface is provided to the user for modifying the values in the authorized ranges.

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: Methods, apparatus and data stream are described to encode, transmit and decode an atlas-based representation of a 3D scene based on a multiplane image (MPI) representation in which a depth component is encoded in each layer. Layers of the MPI are clustered on a transparency basis to generate texture, transparency and depth patch pictures. Patch pictures are packed in at least one atlas image. Metadata associating each patch to a layer and each layer to a depth and a depth quantization law are encoded in the data stream with the at least one atlas. At the decoding side, the MPI with a depth component is retrieved from the data stream and is used to render a viewport image from a viewpoint in the neighborhood of the center of the MPI.

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 parametric function and a list of parameter values for the identified parametric function.

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. These data are inserted in the video track of the stream with associated temporal information. The color and depth pictures that are repeated at least two times in a sequence of patches are not packed in the images but inserted in the image track of the stream and are pointed by color or geometry data.

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 parametric function and a list of parameter values for the identified parametric function.

Abstract: The purpose of the invention is a method for activating a mobile device in a network comprising at least one display device being coupled to a sensor. This method is characterised by the fact that it comprises: detecting the mobile device via the sensor coupled to the display device; displaying a device representative of the detected mobile device, called a virtual device, on the display device such that the position of the virtual device on the display screen is linked to the position of the mobile device in the capture field of the sensor; activating the mobile device in the network when a determined action is applied by the user to the mobile device. Another purpose of the invention is a display device and a system implementing the method.

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 apparatus for encoding and decoding a volumetric scene are disclosed. A set of attribute and geometry patches is obtained by projecting samples of the volumetric scene onto the patches according to projection parameters. If the geometry patch is comparable to a planar layer located at a constant depth according to the projection parameters, only the attribute patch is packed in an attribute atlas image and the depth value is encoded in metadata. Otherwise, both attribute and geometry patches are packed in an atlas. At the decoding, if metadata for an attribute patch indicates that its geometry may be determined from the projection parameters and a constant depth, the attributes are inverse projected on a planar layer. Otherwise, attributes are inverse projected according to the associated geometry patch.

Abstract: Methods, devices and stream are disclosed to encode and decode a scene (such as a point cloud) in the context of a patch-based transmission of a volumetric video content. Attributes of points of the scene are projected onto patches. Every point has a geometry attribute. For other attributes, like transparency of displacement attribute, some points may have no value. According to the present principles, each attribute is encoded in a different atlas with its own layout. This allow to save pixel rate in memory of the renderer.

Abstract: A method for activating a mobile device in a network is disclosed wherein the network further comprises at least one display device coupled to a sensor. This method comprises: detecting the mobile device via the sensor coupled to the display device; displaying a virtual device representative of the detected mobile device on the display device such that the position of the virtual device on the display device is linked to the position of the mobile device in the capture field of the sensor; activating the mobile device in the network when a determined action is applied by the user to the mobile device. A display device and a system implementing the method are further disclosed.

Abstract: To represent a 3D scene, the MPI format uses a set of fronto-parallel planes. Different from MPI, the current MIV standard accepts a 3D scene represented as sequence input pairs of texture and depth pictures as input. To enable transmission of an MPI cube via the MIV-V3C standard, in one embodiment, an MPI cube is divided into empty regions and local MPI partitions that contain 3D objects. Each partition in the MPI cube can be projected to one or more patches. For a patch, the geometry is generated as well as the texture attribute and alpha attributes, and the alpha attributes may be represented as a peak and a width of an impulse. In another embodiment, an MPI RGBA layer of the MPI is cut into sub-images. Each sub-image may correspond to a patch, and the RGB and alpha information of the sub-image are assigned to the patch.

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 devices for encoding and decoding data representative of a 3D scene are disclosed. A set of first patches is generated from a first MVD content acquired from a first region of the 3D scene. A patch is a part of one of the views of the MVD content. A set of second patches is generated from a second MVD content acquired from a second region of the 3D scene. An atlas packing first and second patches is generated and associated with metadata indicating, for a patch of the atlas, whether the patch is a first or a second patch At the decoding side, first patches are used for rendering the viewport image and second patches are used for pre-processing or post-processing the viewport image.

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. 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 streams are disclosed for encoding a depth atlas representative of the geometry of a volumetric video. Views to be encoded are analyzed to detect regions of the views with simple depth or color, that is regions for which the depth or color has a local variance lower than a given threshold. Resolution of such regions is reduced and the atlas comprises first regions in full resolution and downscaled second regions. Metadata indicating whether a patch is a downscaled region and, if so the downscaling factor, are associated with the atlas in the data stream. The decoder uses these metadata to compose the view from different patches.

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.