Abstract: The present principles relate to a method and device method for encoding depth values of orthogonally projected points of a point cloud onto a projection plane. The present principles also relate to a method and device for decoding a point cloud, a computer readable program and a video signal.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding using entropy coding of quantized transform coefficients. The method comprises: determining context model indices for one or more syntax elements of quantized transform coefficients of a transform block, wherein different context model indices are obtained for quantized transform coefficients in different regions of the transform block and a single context index is used for at least one region of the transform block; and selecting for the one or more syntax elements associated with a particular quantized transform coefficient one of several context models based on the determined content model index.

Abstract: This method for up-sampling a point cloud representing a 3D object, comprises: —detecting (2) points belonging to at least one under-sampled region of the point cloud on the basis of at least one desirable sampling rate (K); —obtaining (12), for each detected point, an associated tangent plane; —inserting (14) in the point cloud at least one neighboring point of each detected point if a distance between the neighboring point and the tangent plane associated with the detected point is less than a first threshold.

Abstract: In video coding, a transform can be selected from multiple transform sets. To efficiently implement multiple transforms, a unified architecture of implementing the Discrete Trigonometric Transforms (DTTs) or flipped DTT can be used. In the proposed unified architecture, the relationships between the transforms are utilized. In particular, all transforms can be implemented based on DCT-II, DCT-IV, a reverse order operation, and a sign changing operation for odd elements. The DCT-II can be implemented at a minimum size, and other sizes for DCT-II can be implemented recursively from the minimum size DCT-II and DCT-IV at various sizes. In one example, the multiple transforms are {DCT-II, DST-II, DCT-III, DST-III, DCT-IV, DST-IV}. The relationships between transforms can also be used to guide the design of additional transforms that can be implemented by the unified architecture.

Abstract: The disclosure discloses methods and devices for transmitting and rendering a 3D scene.

Abstract: A method for encoding a block is disclosed. To this aim, a split mode is determined based on a rate-distortion optimization using a texture-based split prediction set obtained for the block. As an example, the split mode is determined by adapting the texture-based split prediction set according to at least one of a binary or triple split mode non-redundancy constraint or a heuristic-based split mode set pruning. The block is finally encoded using the determined split mode.

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: The present embodiments relate to a method and apparatus comprising: —deriving chroma components (I) of a third image by correcting chroma components (II) of a second image according to a luma component of said second image and a reconstructed component obtained by applying a mapping function to said luma component (III) of said second image, said chroma components (II) of the second image being obtained by applying a conversion matrix to components (IV) of a first image; and —adapting coefficients of the conversion matrix which are relative to a chroma component of said third image independently of coefficients of the conversion matrix which are relative to another chroma component of said third image to ensure that there is no clipping on chroma components of the third image.

Abstract: Methods and apparatuses for video coding and decoding are provided. The method of video encoding includes accessing a bin of a syntax element associated with a block in a picture of a video, determining a context for the bin of the syntax element associated with the syntax element and entropy encoding the bin of the syntax element based on the determined context wherein either the bin of the syntax element is based on the relevance of a prediction by a neural network of the syntax element or the probability associated to the context is determined by a neural network. A bitstream formatted to include encoded data, a computer-readable storage medium and a computer-readable program product are also described.

Abstract: A method provides translation of metadata related to enhancement of a video signal according to a first high dynamic range video distribution type into metadata related to enhancement of a video signal according to a second high dynamic range video distribution type. Translation is done between a value of a first metadata set corresponding to a first type of high dynamic range video and a value of a second metadata set corresponding to a second type of high dynamic range video and uses an association that may be stored in a lookup table that is determined according to differences between a test image reconstructed using the metadata of first type and the same image reconstructed using the metadata of second type. A receiver apparatus and a transmitter apparatus comprising the translation method are also disclosed.

Abstract: A block of video data is split using one or more of several possible partition operations by using the partitioning choices obtained through use of a texture-based image partitioning. In at least one embodiment, the block is split in one or more splitting operations using a convolutional neural network. In another embodiment, inputs to the convolutional neural network come from pixels along the block's causal borders. In another embodiment, boundary information, such as the location of partitions in spatially neighboring blocks, is used by the texture analysis. Methods, apparatus, and signal embodiments are provided for encoding.

Abstract: A method includes encoding target parameters describing characteristics for a target color space for a video picture to be displayed in the target color space and encoding color transform parameters that facilitate remapping the video picture to the target color space. A method includes decoding target parameters describing characteristics for a target color space for a video picture to be displayed in the target color space, decoding color transform parameters that facilitate remapping the video picture to the target color space, remapping the video picture to the target color space utilizing at least one of the decoded color transform parameters, and displaying the remapped video picture in the target color space. The color transform parameters represent at least three successively applied color transforms comprising a first color transform followed by a second color transform followed by a third color transform. Related apparatus for each method are described.

Abstract: A video encoder or decoder processes portions of video using virtual temporal affine motion candidates. Under the general aspects, virtual temporal affine candidates are created using only the classical temporal motion buffer information, avoiding the storage of additional affine parameters in a temporal motion buffer. A motion field for encoding or decoding a video block is generated based on the virtual temporal affine candidates. In one embodiment, collocated motion candidates are rescaled by adjusting the picture order count of the determined motion field. In another embodiment, resolution adaptation is performed to enable a current motion buffer to correspond to a reference motion buffer.

Abstract: A medium dynamic range video signal and associated metadata are received, wherein the metadata include data representative of a peak luminance value of the signal. The medium dynamic range video signal is processed in a first mode to reconstruct a high dynamic range video signal based on a received standard dynamic range video signal and associated metadata if the peak luminance value of the medium dynamic range video signal is smaller than the peak luminance value of a presentation display, and in a second mode to optimize a received high dynamic range video signal for a rendering device if the peak luminance value of the medium dynamic range video signal is greater than the peak luminance value of the presentation display.

Abstract: Methods and apparatus are provided for determining quantization parameter predictors from a plurality of neighboring quantization parameters. An apparatus includes an encoder for encoding image data for at least a portion of a picture using a quantization parameter predictor for a current quantization parameter to be applied to the image data. The quantization parameter predictor is determined using multiple quantization parameters from previously coded neighboring portions. A difference between the current quantization parameter and the quantization parameter predictor is encoded for signaling to a corresponding decoder.

Abstract: When dependent scalar quantization is used, the choice of the quantizer depends on the decoding of the preceding transform coefficient, and the entropy decoding of a transform coefficient depends on quantizer choice. To maintain high throughput in hardware implementations for transform coefficient entropy coding, several decision schemes of the scaler quantizer are proposed. In one implementation, the state transition and the context model selection are based on only regular coded bins. For example, the state transition can be based on the sum of the SIG, gt1 and gt2 flags, the exclusive-or function of the SIG, gt1 and gt2 flags, or based on only the gt1 or gt2 flag. When a block of transform coefficients is coded, the regular mode bins can be coded first in one or more scan passes, and the remaining bypass coded bins are grouped together in another one or more scan passes.

Abstract: At least one of the present embodiments generally relates to a method and an apparatus for video encoding and decoding, and more particularly, to a method and an apparatus for low-complexity bi-directional intra prediction. For example, a subset of a plurality of directional intra prediction modes is selected based on a shape of a current block of a picture being encoded or decoded. For a selected intra prediction mode in this subset, a sample value is bi-directionally intra predicted by using two predictors. The two predictors are substantially on a line based on a direction corresponding to the selected directional intra prediction mode. The bi-directional intra prediction may be only applied to large luma blocks, but not chroma blocks in order to reduce the computational complexity. When bi-directional intra prediction is used, the smoothing filtering may be omitted in intra prediction to further reduce the complexity.

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: At least a method and an apparatus are presented for efficiently encoding or decoding video. For example, one or more prediction models are determined respectively for one or more prediction candidates used for the video encoding based on one or more control point motion vectors of a current block of the video being encoded or decoded. It is determined from the one or more control point motion vectors that a first prediction model of the one or more prediction models may be a translational prediction model. It is also determined from the one or more control point motion vectors that a second prediction model of the one or more prediction models is to be an affine prediction model. The video is encoded or decoded based on a candidate list comprising the one or more prediction candidates determined respectively from the one or more prediction models.

Abstract: A block of video data is split using at least one splitting rule and coded using existing transform sizes through one of several embodiments. In one embodiment, the block is split using a triple tree splitting operation if said at least two rectangular sub-blocks can be achieved with two successions of split operations with at least one triple tree split. In another embodiment, the video block is split using an asymmetric binary tree splitting if said at least two rectangular sub-blocks can be achieved with two successions of split operations with at least one asymmetric binary split. In another embodiment, a video block is split using successive splits, using both of the rules of the other embodiments.