A method of coding 4:2:2 or 4:4:4 video data comprises predicting luminance and/or chrominance samples of an image from other respective reference samples derived from the same image according to a prediction mode associated with a sample to be predicted, the prediction mode being selected for each of a plurality of blocks of samples, from a set of two or more candidate prediction modes; detecting differences between the samples and the respective predicted samples; selecting a frequency-separation transform from two or more candidate frequency separation transforms according to the prediction mode associated with a current block of samples using a mapping between transform and prediction mode, the mapping between different, as between chrominance and luminance samples, for at least the 4:4:4: format; and encoding the detected differences by frequency-separating the differences, using the selected frequency-separation transform.

A video coding or decoding method operable to generate blocks of quantized spatial frequency data by quantizing the video data according to a selected quantization step size and a matrix of data modifying the quantization step size for use at different respective block positions within an ordered block of samples, the method being operable with respect to at least two different chrominance subsampling formats.

A point cloud encoder including an input interface to accept a dynamic point cloud including a sequence of point cloud frames of a scene. A processor encodes blocks of a current point cloud frame to produce an encoded frame. Wherein, for encoding a current block of the current point cloud frame, a reference block is selected similar to the current block according to a similarity metric to serve as a reference to encode the current block. Pair each point in the current block to a point in the reference block based on values of the paired points. Encode the current block based on a combination of an identification of the reference block and residuals between the values of the paired points. Wherein the residuals are ordered according to an order of the values of the points in the reference block. A transmitter transmits the encoded frame over a communication channel.

A video coding or decoding method using inter-image prediction to encode input video data in which each chrominance component has 1/Mth of the horizontal resolution of the luminance component and 1/Nth of the vertical resolution of the luminance component, where M and N are integers equal to 1 or more, comprises: storing one or more images preceding a current image; interpolating a higher resolution version of prediction units of the stored images so that the luminance component of an interpolated prediction unit has a horizontal resolution P times that of the corresponding portion of the stored image and a vertical resolution Q times that of the corresponding portion of the stored image, where P and Q are integers greater than 1; detecting inter-image motion between a current image and the one or more interpolated stored images so as to generate motion vectors between a prediction unit of the current image and areas of the one or more preceding images; and generating a motion compensated prediction of the prediction unit of the current image with respect to an area of an interpolated stored image pointed to by a respective motion vector; in which the interpolating step comprises: applying a xR horizontal and xS vertical interpolation filter to the chrominance components of a stored image to generate an interpolated chrominance prediction unit, where R is equal to (U?M?P) and S is equal to (V?N?Q), U and V being integers equal to 1 or more; and subsampling the interpolated chrominance prediction unit, such that its horizontal resolution is divided by a factor of U and its vertical resolution is divided by a factor of V, thereby resulting in a block of MP?NQ samples.

A method of coding 4:2:2 or 4:4:4 video data comprises predicting luminance and/or chrominance samples of an image from other respective reference samples derived from the same image according to a prediction mode associated with a sample to be predicted, the prediction mode being selected for each of a plurality of blocks of samples, from a set of two or more candidate prediction modes; detecting differences between the samples and the respective predicted samples; selecting a frequency-separation transform from two or more candidate frequency separation transforms according to the prediction mode associated with a current block of samples using a mapping between transform and prediction mode, the mapping between different, as between chrominance and luminance samples, for at least the 4:4:4 format; and encoding the detected differences by frequency-separating the differences, using the selected frequency-separation transform.

Techniques are described in which a decoder is configured to receive an input data block and apply an inverse non-separable transform to at least part of the input data block to generate an inverse non-separable transform output coefficient block. The applying the inverse non-separable transform comprises assigning a window, assigning a weight for each position inside the assigned window, and determining the inverse non-separable transform output coefficient block based on the assigned weights. The decoder is further configured to forming a decoded video block based on the determined inverse non-separable transform output coefficient block, wherein forming the decoded video block comprises summing the residual video block with one or more predictive blocks.

Decoding corresponding to a first array of quantized coefficients including an N?M array corresponding to a first block and data corresponding to a second array including an N?M array corresponding to a second block. Deriving a first array of orthogonal transform coefficients from the first array of quantized coefficients by using at least a first quantization matrix of an N?M array of elements, and derives a second array of orthogonal transform coefficients from the second array by using at least a second quantization matrix of an N?M array of elements. Performing inverse orthogonal transform on the first array of orthogonal transform coefficients to generate a P?Q array of pixels of first prediction residuals, and performs inverse orthogonal transform on the second array of orthogonal transform coefficients to generate an N?M array of pixels of second prediction residuals.

A video coding or decoding method operable to generate blocks of quantised spatial frequency data by quantising the video data according to a selected quantisation step size and a matrix of data modifying the quantisation step size for use at different respective block positions within an ordered block of samples, the method being operable with respect to at least two different chrominance subsampling formats.

The current application is directed to flexible methods for motion-vector-based encoding of macroblocks within video frames. The flexible methods for encoding video-frame macroblocks provide for segmentation of a video-frame block and encoding the segmented video-frame block by a segmented-block motion vector that includes a reference to a segmentation-defining region of a segmentation map and that also includes references to sources of intensity-and-color data for each segment. Segmented-block motion vectors provide for flexible segmentation-based encoding of video-frame blocks without sacrificing the coding efficiencies attendant with conventional motion-vector-based video encoding.

Encoding and decoding using prediction dependent transform coding are provided. Encoding and decoding using prediction dependent transform coding may include identifying a current input block from a current input frame from an input video stream, generating a prediction block for the current input block, generating a residual block based on a difference between the current input block and the prediction block, generating, by a processor in response to instructions stored on a non-transitory computer readable medium, an encoded block by encoding the residual block based on the prediction block using the using prediction dependent transform coding, including the encoded block in an output bitstream, and outputting or storing the output bitstream.