Abstract: A method for intra prediction is provided, the method including: obtaining a predicted sample value for a sample of the block; obtaining a scaling factor value according to an intra prediction mode for the current coding block, and according to at least one of: a height of the current coding block, or a width of the current coding block, or a size of a subpartition of the current coding block; determining a first weight value based on the scaling factor value; determining a second weight value based on the scaling factor value; calculating an additional value as a weighted sum of a top reference sample value and a left reference sample value, by weighting the top reference sample value with the first weight and the left reference sample value with the second weight; and obtaining a modified predicted sample value according to the additional value and the predicted sample value.

Abstract: The disclosure relates to methods and a coding apparatus for intra prediction using a linear model. The method includes: determining a filter for a luma component of a current block based on a chroma format of a picture that the current block belongs to, and applying the determined filter to an area of reconstructed luma samples of the luma component of the current block and/or luma samples in selected position neighboring to the current block, to obtain filtered reconstructed luma samples. The method further includes: obtaining, based on the filtered reconstructed luma samples, linear model coefficients. Cross-component prediction is performed based on linear model coefficients of the linear model derivation and the filtered reconstructed luma sample.

Abstract: A device and method for intra-predicting a rectangular and non-square video coding block, the device including an intra-prediction apparatus configured for intra-predicting a rectangular and non-square video coding block according to a set of directional intra-prediction modes distributed over a set of directional ranges, where the intra-prediction apparatus being configured for configured for intra-predicting the rectangular and non-square video coding block includes the intra-prediction apparatus being configured to select a directional range from the set of directional ranges, and determine a number of directional intra-prediction modes of the selected directional range according to a size of a block.

Abstract: An encoding apparatus is described for signaling an extension directional intra-prediction mode within a set of directional intra-prediction modes, the set of directional intra-prediction modes comprising predetermined directional intra-prediction modes and the extension directional intra-prediction mode. The encoding apparatus comprises a mode mapping unit selecting a predetermined directional intra-prediction mode, the selected predetermined directional intra-prediction mode being associated with an intra mode index, and mapping the extension directional intra-prediction mode onto the selected predetermined directional intra-prediction mode. A signaling unit generates a signaling indicator comprising at least one of the intra mode index and a flag value. An intra-prediction unit intra-predicts pixel values of pixels of a rectangular video coding block on the basis of the extension directional intra-prediction mode for providing a predicted rectangular video coding block.

Abstract: A method of intra prediction of a coding block, performed by a decoder, the method comprising: obtaining a bitstream for the coding block; obtaining a value of intra prediction mode according to the bitstream; obtaining a value of an index for the coding block in accordance with the bitstream; obtaining a set of reference samples for the coding block, the set of reference samples comprises samples of a reconstructed block and additional samples; when the value of the index for the coding block is not equal to the predefined value, the set of reference samples comprises only of samples of the reconstructed block; obtaining a prediction value of a sample comprised in the coding block, according to the value of intra prediction mode for the coding block and the set of reference samples.

Abstract: A method for an intra predicting process of a video block is provided. The method comprises: obtaining a predicted sample value for a sample of the current coding block; obtaining a scaling factor value according to an intra prediction mode for the current coding block, and according to a height of the current coding block and/or a width of the current coding block; determining a first weight based on the scaling factor value; determining a second weight based on the scaling factor value; calculating an additional value as a weighted sum of a top reference sample value and a left reference sample value, by weighting the top reference sample value with the first weight and weighting the left reference sample value with the second weight; obtaining a modified predicted sample value according to the additional value and the predicted sample value; and outputting the modified predicted sample.

Abstract: A method and apparatus for adaptively processing video samples in a video signal frame, the video samples being arranged in a Largest Coding Unit. The method comprises extracting a plurality of video samples from the Largest Coding Unit, calculating a correction offset for a first video sample of the extracted plurality of video samples upon the basis of a first value of the first video sample and a second value of a second video sample of the extracted plurality of video samples, and weighting the first video sample with the correction offset.

Abstract: A method for constructing a Most Probable Mode (MPM) list includes classifying each intra prediction mode derived from a neighboring block either as a valid or invalid subject to the mode direction and the position of its source block. Valid and invalid modes are considered most and least probable modes, respectively.

Abstract: The present disclosure provides embodiments for coding and decoding signs of transformation coefficients which is applicable, for instance, in image and/or video coding and decoding. In particular, a plurality of the signs are predicted and only a prediction error signal is embedded in the bitstream. The prediction error signal may have a distribution which can be efficiently coded with CABAC or another variable length (entropy) coding. In order to perform the prediction of the signs efficiently, the signs of a plurality of coefficients of a transformed image block are predicted based on a cost function including transformed difference between adjacent pixels neighboring the transformed image block and prediction of the adjacent pixels calculated based on a prediction signal of the image block.

Abstract: A method includes obtaining a first control parameter in a sequence parameter set (SPS) level, wherein a first value of the first control parameter in the SPS level indicates that a smoothing is not applied for any block of a sequence, a second value of the first control parameter in the SPS level indicates that the smoothing is applied for each block of the sequence, and obtaining a second control parameter in a slice header when a third value of the first control parameter in the SPS level is equal to a predefined value, wherein a first value of the second control parameter indicates that the smoothing is applied for each block of a slice.

Abstract: An intra-prediction apparatus and method are provided for extending a set of predetermined directional intra-prediction modes of a rectangular video coding block. The intra-prediction apparatus determines an aspect ratio of the rectangular video coding block, and determines a complementary angle range based on the aspect ratio. The apparatus then selects a complementary direction within the complementary directional range, and adds an extension directional intra-prediction mode associated with the complementary direction to the set of predetermined directional intra-prediction modes. Based on the extension directional intra-prediction mode, the apparatus intra-predicts pixel values of pixels of the rectangular video coding block.

Abstract: Devices and methods of intra prediction of a block of a picture are provided. In various embodiments, information indicating an Intra Sub-Partitions (ISP) split type can be obtained. A value of a filter flag can be set based on the ISP split type. For instance, the value of the filter flag can be set to 0 when the ISP split type does not indicate not to split a current block. A set of coefficients of an interpolation filter can then be selected according to the value of the filter flag. For instance, fG coefficients or fC coefficients can be selected based on the value of the filter flag. Still in those embodiment, the selected set of coefficients can be applied to reference samples. In some embodiments, the method removes mode dependency during selection of interpolation filter type. This could increase encoding or decoding efficiency.

Abstract: It is provided a method for combined inter-intra prediction of a current block in video coding wherein combined intra-inter-prediction is used for providing a prediction block and wherein the weights for the intra- and inter-prediction blocks used to obtain the prediction block can be finely tuned. In particular, the method comprises determining prediction information for a neighboring block adjacent to the current block, the prediction information comprising a prediction mode used for prediction of the neighboring block, determining whether matrix-based intra prediction, MIP, is to be used for the prediction of the current block and predicting the current block as a weighted sum of an intra-predicted block and an inter-predicted block, wherein weights of the inter-predicted block and the intra-predicted block are determined based on the prediction information for the neighboring block and the determining whether MIP is to be used for the prediction of the current block.

Abstract: An inter prediction method includes determining whether a non-rectangular inter prediction mode is allowed for a group of blocks; obtaining one or more inter prediction mode parameters and weighted prediction parameters for the group of blocks; and obtaining prediction value of a current block based on the one or more inter prediction mode parameters and weighted prediction parameters, wherein one of the inter prediction mode parameters indicates reference picture information for the current block, and wherein the group of blocks comprises the current block.

Abstract: The present disclosure relates to moving picture processing, and in particular to cases where non-rectangular partitioning modes are used for the inter-prediction in a combination with weighted prediction (WP) for coding fades. Non-rectangular modes refer to those inter-prediction modes, in which case a current block is partitioned/sliced in a non-rectangular way (slices). Such modes may be triangular (TMP) or geometric (GEO) prediction. The aim of the invention is to harmonize non-rectangular partitioning modes with WP by way of disabling TMP/GEO when WP is applied. This may be accomplished by checking whether all reference pictures for a current slice are disabled, and if this is the case to disable the slice-level WP for non-rectangular prediction units. Whether the reference pictures are disabled may be determined based on conditions applied on set values, for example, of luma/chroma flags, which refer to the reference pictures.

Abstract: A method of video coding, wherein the method comprises inter-prediction processing of a first block, wherein the inter-prediction processing comprises subpixel interpolation filtering of samples of a reference block; intra-prediction processing of a second block, wherein the intra-prediction processing comprises subpixel interpolation filtering of reference samples; wherein the method further comprises selecting interpolation filter coefficients for the subpixel interpolation filtering based on a subpixel offset between integer reference sample positions and fractional reference samples' positions, wherein for the same subpixel offsets the same interpolation filter coefficients are selected for intra-prediction processing and inter-prediction processing.

Abstract: A method includes: obtaining one or more parameters of a geometric merge (GEO) inter prediction mode for a current coding block; defining a size of a subblock that is smaller than a size of the current coding block; specifying a position of the subblock within the current coding block, so that either two or three sides of the subblock coincide with sides of the current coding block; determining one or more allowed split directions of a triangle partitioning mode (TPM) for the subblock depending on which of the sides of the subblock coincide with the sides of the current coding block; and obtaining one or more predicted samples for the current coding block by using the TPM partitioning performed for the subblock in accordance with the size of the subblock, the position of the subblock within the current coding block and a TPM split direction of the subblock.

Abstract: A method of an inter prediction process performed by a processing unit of a coding system comprises deriving combined linear combination parameters from two sets of linear combination parameters, where a first set of linear combination parameters is independent from the position of the to-be-predicted block and a second set of linear combination parameters depends on the position of the to-be-predicted block; and obtaining the value of the to-be-predicted sample using the combined linear combination parameters and predicted values of at least two samples belonging to different reference blocks of the to-be-predicted block.

Abstract: A computer-implemented method of determining whether an inter prediction process is enabled is provided in this application, the method comprising: obtaining an indication, the indication indicating whether a slice-level weighted prediction mechanism is to be enabled in the inter prediction process; determining, based on the indication, whether a non-rectangular merge mode or whether the slice-level weighted prediction mechanism is to be enabled in the inter prediction process. Furthermore, an encoder for encoding a datastream, like a video stream, using an inter prediction process and a decoder for decoding an encoded datastream, like an encoded video stream, using an inter prediction process, are provided.

Abstract: The present disclosure provides example computer-implemented methods and decoders of video coding for prediction of a block using an inter prediction mode to obtain predicted samples for the block. One example method includes defining a size of a subblock that is smaller than the size of the block. A position of the subblock within the block is specified. One or more allowed split directions of a triangle partitioning mode (TPM) is determined for the subblock depending on which of the sides of the subblock coincide with the sides of the block. One or more predicted samples for the block is obtained by using TPM partitioning performed for the subblock in accordance with the size of the subblock, the position of the subblock within the block, and TPM split direction of the subblock. The block is reconstructed based on the one or more predicted samples.