Abstract: A picture encoding apparatus configured to hierarchically partition a block of picture data into sub-blocks; determine that a sub-block being coded belongs to an unequally-sized partitioned block; prepare a list of neighboring blocks for the sub-block of the unequally-sized partitioned block based on a size of the sub-block of the unequally-sized partitioned block and a partitioning type of at least one neighboring block of the unequally-sized partitioned block; and derive a context model that is used to encode split information of the sub-block of the unequally-sized partitioned block into a bit stream based on the prepared list of neighboring blocks.

Abstract: Devices and methods of intra prediction of a block of a picture are provided. The method includes obtaining reference samples of a block, and determining a value of a predicted sample based on the reference samples and an intra prediction mode. The method further includes obtaining a value of a multiplier based on at least one dimension of the block, and normalizing the value of the predicted sample based on the value of the multiplier and a value of a shift. The intra prediction mode is INTRA_DC, or INTRA_BI, or horizontal intra prediction mode. By normalizing the value of the predicted sample based on the value of the multiplier and a value of a shift without division operation, the method could increase intra prediction efficiency.

Abstract: A method of decoding encoded video data for providing a residual video coding block is provided. An intra-prediction mode identifier is extracted from the encoded video data. The method includes: generating a predicted video coding block based on a selected intra-prediction mode; pre-selecting a plane-based intra-prediction mode and a further intra-prediction mode, when the extracted intra-prediction mode identifier is equal to a first predefined intra-prediction mode identifier; selecting the plane-based intra-prediction mode or the further intra-prediction mode, based on (a) an additional flag extracted from the encoded video data or (b) a deviation measure; restoring a video coding block based on the residual video coding block and the predicted video coding block. The deviation measure quantifies deviations of a plurality of reference samples from neighboring video coding blocks from a plurality of fitting samples defined by a fitting plane based on the plurality of reference samples.

Abstract: A method of intra prediction of a block, comprising obtaining two lines of reconstructed neighboring samples; deriving a set of reference samples based on the two lines of reconstructed neighboring samples; obtaining a set of MIP coefficients based on a intra prediction mode obtained from a bitstream, wherein a MIP coefficient CMIP of the set of MIP coefficients is obtained based on CMIP=vsgn·(q<<s), where q is a magnitude of the MIP coefficient, wherein s is a left shift value and vsgn is a sign value of the MIP coefficient; and obtaining a prediction block based on the set of reference samples and the set of MIP coefficients, wherein a reconstruct picture is obtained based on the prediction block.

Abstract: Devices and methods for intra prediction of DC intra prediction mode are provided. The method includes: obtaining a value of an intra prediction reference line index of a transform block; obtaining prediction samples of the transform block based on reference samples from a reference line. The reference line is indexed by the value of the intra prediction reference line index. The method introduces a harmonization of MRL and non-directional intra prediction (i.e. DC). The harmonization consists of aligning the reference samples from a reference line, which is indexed by the value of the intra prediction reference line index.

Abstract: The present invention relates to method and apparatus for motion vector derivation for affine based inter prediction of chroma subblocks based on chroma format. The method includes: determining chroma scaling factors in horizontal and vertical directions based on chroma format information, wherein the chroma format information indicates a chroma format of a current picture which the current image block belongs to; determining a set (S) of luma subblocks of the luma block based on values of the chroma scaling factors; determining a motion vector for a chroma subblock of the chroma block based on motion vectors of one or more luma subblocks in the set (S) of luma subblocks.

Abstract: Methods, systems, devices, and apparatus for image processing are provided. In one aspect, a method includes: intra-predicting a block of an image based on reference samples of the image, the reference samples being arranged in one or more reference sample sets each including a coherent set of reference samples and including one or more reference samples adjoining the block; segmenting each of the one or more reference sample sets into a sequence of three or more subsets including a first subset, a last subset, and one or more intermediary subsets located therebetween; determining a weight value for each subset, weight values of the one or more intermediary subsets being lower than weight values of the first subset and the last subset; fitting a plane to the reference samples of the image using the determined weight values; and generating an intra-predicted block based on the plane.

Abstract: A device is configured to select a directional intra-prediction mode from a set of directional intra-prediction modes, wherein each directional intra-prediction mode corresponds to a different intra-prediction angle. Further, the device is configured to select a filter from a set of filters based on the selected directional intra-prediction mode. Further, the device is configured to determine, for a given prediction sample of the prediction block, a reference sample from a set of reference samples based on the selected directional intra-prediction mode, and apply the selected filter to the determined reference sample.

Abstract: A video coding device, comprising a sequence of filters that are configurable by one or more primary parameters and one or more secondary parameters, and a filter controller configured to adjust the one or more secondary parameters based on the one or more primary parameters and based on a strength criterion of the sequence of filters.

Abstract: The present invention relates to the field of picture processing. Especially, the invention deals with improving intra prediction (such as the chroma intra prediction) using a cross component linear model (CCLM) and more particularly to spatial filtering used in cross-component linear model for intra prediction with different chroma formats. An apparatus, an encoder, a decoder and corresponding methods for cross-component prediction for a picture, in which the set of down-sampling filters applied during the prediction depends on a chroma format, that may be one of multiple supported chroma formats are provided, so as to improve coding efficiency.

Abstract: A method determines an intra-prediction mode for decoding a block of a picture encoded in a bitstream. The method includes: inferring a value of an intra-prediction mode of the block to a value indicating a non-angular mode in a case where prediction information associated with the block indicates that the intra-prediction mode is not an angular mode and that intra-sub-partitioning is applied to the block.

Abstract: Embodiments provide methods and apparatus for illumination compensation for inter prediction coding of a picture, e.g. for video encoding and decoding. The methods may comprise: obtaining inter-predicted sample values for a current block of the picture; obtaining a first target value (xA) and a second target value (xB) of neighboring samples from a set L of neighboring samples of a reference block, wherein said set L comprises neighboring samples of at least one reference block of the current block, and obtaining corresponding positions A of the sample having the first target value and B of the sample having the second target value relative to the position of the reference block; obtaining respective values of neighboring samples (yA, yB) of the current block at the obtained positions A and B relative to the position of the current block; obtaining values of updating parameters using the calculated values; and updating the values of the inter-predicted samples based on the updating parameters.

Abstract: Devices and methods of directional intra prediction for chroma component of a picture are provided. The method includes obtaining an initial intra prediction mode of the chroma component, and deriving a chroma intra prediction mode (intraPredModeC) from a look up table (LUT) by using the initial intra prediction mode of the chroma component. The chroma component has different subsampling ratios in horizontal and vertical directions. The method further includes performing wide-angle mapping on the chroma intra prediction mode (intraPredModeC) to obtain a modified intraPredModeC; obtaining an angle parameter for the chroma component based on the modified intraPredModeC; and obtaining predicted samples of the chroma component based on the angle parameter. The method provides the minimum number of entries in the LUT that is used to determine chroma intra prediction mode from the initial chroma intra prediction mode.

Abstract: An intra prediction method is described. The method can include determining a prediction value for a sample of a current block from one or more reference samples outside the current block by using an intra predication mode. The method can also include deriving a weighted prediction value, when one or more predefined conditions are not satisfied, wherein the one or more predefined conditions relate to at least one of a width and/or a height of the current block and the intra prediction mode. Furthermore, the method can include coding the current block using the weighted prediction value, when the one or more predefined conditions are not satisfied.

Abstract: The present disclosure relates to apparatuses and methods for intra- or inter-prediction for video encoding and decoding. In one embodiment, a method includes obtaining a reference sample and obtain a fractional sample position p; filtering the reference sample using a subpixel interpolation filter to obtain a predicted sample value. In the method, the filter coefficients of the subpixel interpolation filter satisfy a linear combination of p and a filter strength parameter S.

Abstract: The present disclosure relates to intra- or inter-prediction for video encoding and decoding. For that purpose, an apparatus and methods obtain a reference sample and a subpixel offset value. A 4-tap interpolation filter is used to filter the reference sample to obtain a predicted sample value. The filter coefficients c0, c1, c2, and c3 of the 4-tap interpolation filter satisfy c 0 = 16 - p 2 , c 1 = 16 + 16 - p 2 , c 2 = 16 + p 2 , and ? ? c 3 = p 2 , with p being a fractional part of the value of the subpixel offset.

Abstract: Apparatuses and methods for encoding and decoding are provided. The method for intra predicting a chroma sample of a block by applying cross-component linear model includes: obtaining reconstructed luma samples; determining maximum and minimum luma sample values based on the reconstructed luma samples; obtaining a difference of the maximum and minimum luma sample values. The method also includes: fetching a value out of a lookup table (LUT) by using a set of bits as an index, the set of bits following a position of the most-significant bit; obtaining linear model parameters based on the fetched value; and calculating a predicted chroma sample value by using the obtained linear model parameters. The efficiency to fetch the value out of the LUT is increased.

Abstract: Apparatuses and methods for intra predicting a block are described. The method of intra predicting a current block can include obtaining a predicted sample value from one or more reference sample values by using an intra prediction mode, obtaining at least one additional reference sample value in accordance with the intra prediction mode, and obtaining a thresholded additional reference sample value based on the additional reference sample value. The method can also include calculating an additional value from the thresholded additional reference sample value, multiplying the predicted sample value by a sample weighting factor, resulting in a weighted predicted sample value, adding the additional value to the weighted predicted sample value, resulting in a non-normalized predicted sample value, and normalizing the non-normalized predicted sample value, resulting in a normalized predicted sample values. The accuracy for the intra prediction is thus increased.

Abstract: An intra-prediction method includes: determining, by an intra-prediction apparatus, a directional intra-prediction mode for a rectangular video coding block from an extended set of directional intra-prediction modes, wherein the extended set of directional intra-prediction modes includes extended directional intra-prediction modes and conventional directional intra-prediction modes and determining, by the intra-prediction apparatus, a plurality of available reference samples based on a direction of the directional intra-prediction mode. The method further includes: intra-predicting, by the intra-prediction apparatus, pixel values of pixels of the rectangular video coding block based on the plurality of available reference samples.

Abstract: The present disclosure provides methods and devices of intra predicting a block of a picture. The method comprises for a sample of the block: obtaining a predicted sample value from one or more reference sample values by performing intra-prediction using a DC intra-prediction mode; multiplying the predicted sample value by a sample weighting factor to produce a weighted predicted sample value; adding an additional value to the weighted predicted sample value to produce a non-normalized predicted sample value; and normalizing the non-normalized predicted sample value by an arithmetic right shift; wherein the sample weighting factor is ((2<<p)?wL?wT), wherein p is a parameter of the sample weighting factor, wL is a horizontal weighting factor, and wT is a vertical weighting factor.