Abstract: Techniques for implementing adaptive loop filtering are described. One example method of video processing includes making a first determination, for a conversion between a video unit of a video and a bitstream of the video, a first luma adaptive loop filter, ALF, boundary across which a luma adaptive loop filter is selectively applied to a luma component of the video unit and a second luma ALF boundary; making a second determination, from the second luma ALF boundary, a chroma ALF boundary across which a chroma adaptive loop filter is selectively applied for a chroma component of the video unit; and performing the conversion based on the first determination and the second determination.

Abstract: A method for video processing is described. The method includes determining, for a conversion between a video unit of a video and a bitstream representation of the video, whether to enable a mirrored padding process for padding an unavailable luma sample during an application of a loop filtering tool to the video unit; and performing the conversion based on the determining.

Abstract: Encoding methods and apparatuses include receiving input video data of a current block in a current picture and applying a Cross-Component Adaptive Loop Filter (CCALF) processing on the current block based on cross-component filter coefficients to refine chroma components of the current block according to luma sample values. The method further includes signaling two Adaptive Loop Filter (ALF) signal flags and two CCALF signal flags in an Adaptation Parameter Set (APS) with an APS parameter type equal to ALF or parsing two ALF signal flags and two CCALF signal flags from an APS with an APS parameter type equal to ALF, signaling or parsing one or more Picture Header (PH) CCALF syntax elements or Slice Header (SH) CCALF syntax elements, wherein both ALF and CCALF signaling are present either in a PH or SH, and encoding or decoding the current block in the current picture.

Abstract: The method for decoding an intra-picture prediction mode includes the steps of: determining whether the intra-picture prediction mode of a current prediction unit is identical to a first intra-picture prediction mode candidate or a second intra-picture prediction mode candidate based on bit information: and when the intra-picture prediction mode of the current prediction unit is identical to the first intra-picture prediction mode candidate and/or to the second intra-picture prediction mode candidate, determining whether the first intra-picture prediction mode candidate or the second intra-picture prediction mode candidate is identical to the intra-picture prediction mode of the current prediction unit on the basis of additional bit information, and decoding the intra-picture prediction mode of the current prediction unit.

Abstract: Concepts are described, including encoding, processing and decoding of a data stream having a video encoded thereinto, wherein the video comprises a plurality of pictures, wherein the data stream comprises a plurality of pictures in at least two layers, wherein the pictures of at least one layer are split into a predetermined layer-specific number of subpictures, one or more of the pictures or subpictures of one layer corresponds to one picture or subpictures in one or more other layer, and at least one of the subpictures comprises boundaries for boundary extension for motion compensation, and an indication that at least one of the boundaries of corresponding subpictures or corresponding pictures in different layers are aligned with each other.

Abstract: A method and device for deriving at least one motion information predictor for encoding of an image portion by motion compensation. At least two distinct first and second subsets of motion information predictors of a first set of motion information predictors are provided. Processing of the first subset of motion information predictors and processing of the second subset of motion information predictors is performed to obtain a final set of motion information predictors usable for predicting said image portion from the reference image portion. Processing of the second subset may comprise removing duplicates from among the motion information predictors of said second subset, and may be performed so as to exclude temporal predictors. At least part of the processing of the second subset of motion information predictors may be performed concurrently with at least part of the processing of the first subset of motion information predictors.

Abstract: The present disclosure provides a chroma block prediction method and a device. The method includes: parsing a bitstream to obtain first indication information; downsampling a first luma block by a first filter when a value of the first indication information is a first value or by using a second filter when a value of the first indication information is a second value, to obtain a second luma block; obtaining a plurality of chroma samples and a plurality of luma samples; obtaining linear model coefficients based on the plurality of chroma samples and the plurality of luma samples; and obtaining a prediction value of the current chroma block based on the second luma block and the linear model coefficients.

Abstract: An image decoding apparatus includes: a first filter unit configured to apply a first filter to an image (a luminance image and a chrominance image); a second filter unit configured to apply a second filter to an output image of the first filter; a filter set derivation unit configured to decode a filter coefficient from coded data; and a third filter unit configured to apply a third filter to an output image of the second filter by using the filter coefficient. In a case that the third filter unit performs filter processing for the luminance image by using a luminance output image of the second filter, the third filter unit performs processing of clipping an amount of change of a pixel value through the filter processing within a prescribed range of value.

Abstract: Techniques for context-adaptive binary arithmetic coding (CABAC) coding with a reduced number of context coded and/or bypass coded bins are provided. Rather than using only truncated unary binarization for the syntax element representing the delta quantization parameter and context coding all of the resulting bins as in the prior art, a different binarization is used and only part of the resulting bins are context coded, thus reducing the worst case number of context coded bins for this syntax element. Further, binarization techniques for the syntax element representing the remaining actual value of a transform coefficient are provided that restrict the maximum codeword length of this syntax element to 32 bits or less, thus reducing the number of bypass coded bins for this syntax element over the prior art.

Abstract: An example method of video processing includes determining, for a conversion between a block of a first sub-picture of a video and a bitstream representation of the video, whether to apply a deblocking process across an edge between the block and a neighboring block of a second sub-picture based on whether a loop filtering process is allowed across subpicture boundaries. The method also includes performing the conversion based on the determining.

Abstract: Techniques for implementing adaptive loop filtering are described. One example method of video processing includes making a first determination, for a conversion between a video unit of a video and a bitstream of the video, a first luma adaptive loop filter, ALF, boundary across which a luma adaptive loop filter is selectively applied to a luma component of the video unit and a second luma ALF boundary; making a second determination, from the second luma ALF boundary, a chroma ALF boundary across which a chroma adaptive loop filter is selectively applied for a chroma component of the video unit; and performing the conversion based on the first determination and the second determination.

Abstract: The present invention relates to an image encoding/decoding method and apparatus. The image decoding method according to the present invention may comprise configuring an MPM list based on intra-prediction modes of neighbor blocks of a current block and a number of frequencies of the intra-prediction modes of the neighbor blocks, deriving an intra-prediction mode of the current block based on the MPM list, and performing intra-prediction for the current block based on the intra-prediction mode.

Abstract: A method for inverse discrete cosine transformation (IDCT) in video coding is provided that includes receiving a transform block, identifying a region of non-zero transform coefficients in the transform block using a group significance map corresponding to the transform block, wherein any transform coefficients not in the region have a value of zero, applying a one-dimensional (1D) IDCT to the region of non-zero transform coefficients in a first direction to generate an interim results block, wherein 1D IDCT computations are not performed on transform coefficients outside the region, and applying a 1D IDCT to the interim results block in a second direction to generate a residual block.

Abstract: A method includes receiving a bit stream; determining, using the bit stream, whether an adaptive resolution management mode is enabled; determining, using the bit stream, a scaling factor including a vertical scaling constant component and a horizontal scaling constant component; and reconstructing pixel data of a current block in adaptive resolution management mode and using the determined scaling factor, the reconstructing including scaling the current block horizontally by the horizontal scaling constant component and scaling the current block vertically by the vertical scaling constant component. Related apparatus, systems, techniques and articles are also described.

Abstract: A method for implementing an adaptive colour transform (ACT) mode during image/video encoding and decoding includes performing a conversion between a current video block of a video and a bitstream of the video, wherein the current video block is coded using the ACT mode, wherein the conversion comprises applying an inverse ACT transform on the current video block according to a rule, and wherein the rule specifies that a clipping operation, based on a bit depth of the current video block, is applied to an input of the inverse ACT transform.

Abstract: The present it relates to a video encoding/decoding method and apparatus. The video decoding method according to the present invention may comprise c coding filter information on a coding unit; classifying samples in the coding unit into classes on a per block classification unit basis; and filtering the coding unit having the samples classified into the classes on a per block classification unit basis by using the filter information.

Abstract: According to an embodiment of the present document, a method for increasing the accuracy of in-loop filtering is proposed. In an example, the filtering accuracy of chroma blocks can be improved on the basis of luma blocks by performing a cross component adaptive loop filtering process.

Abstract: A method of performing intra prediction of a current block of a picture of a video sequence, includes determining whether a first flag indicates that an intra prediction mode corresponding to the current block is a directional mode, and based on the first flag being determined to indicate that the intra prediction mode corresponding to the current block is the directional mode, determining an index of the intra prediction mode in an allowed intra prediction modes (AIPM) list, and performing the intra prediction of the current block, using the intra prediction mode corresponding to the determined index in the AIPM list.

Abstract: Systems and techniques for determining a list of geographic location candidates from an image of an environment are described. Open source data indicative of the earth's surface may be obtained and combined into grids to create region data to gain a representation of the earth's surface within each grid cell. An image of an environment may be obtained from an unknown camera. Image characteristics may be compared to the region data to determine error between the image characteristics and projections of the region data. A list of lowest error geographic location candidates may be determined and provided to the user.

Abstract: Method and apparatus for constrained de-blocking filter are disclosed. One method receives input data related to a current block in a current picture at a video encoder side or a video bitstream corresponding to compressed data including the current block in the current picture at a video decoder side, and determines a first boundary associated with the current block, wherein the first boundary corresponds to one vertical boundary or one horizontal boundary of the current block. The method then applies de-blocking process to a reconstructed current block corresponding to the current block to result in a filtered-reconstructed current block, using a plurality of first reference samples at a same side of the first boundary, and replaces a first set of the first reference samples by one or more padding values. The method then generates a filtered decoded picture including the filtered-reconstructed current block.