Abstract: A prediction method for an image block comprising a first prediction sub-block and a second prediction sub-block, the prediction method comprising: parsing a first index from a bitstream, wherein the first index is used to obtain prediction information of the first prediction sub-block; parsing a second index from the bitstream; comparing the first index with the second index; adjusting the second index in the event that the second index is equal to or greater than the first index; and obtaining prediction information of the second prediction sub-block according to the adjusted second index.

Abstract: The present disclosure relates to methods and apparatuses for modifying a quantizer. In particular, within a preliminary set of quantization levels, at least one quantization level is modified based on optimization involving distortion for a predetermined set of input values. At least one another quantization level out of the preliminary set is not modified. The not modified (non-modifiable) quantization level is the minimum clipping value or the maximum clipping value. The modification may facilitate increasing the dynamic range of the quantized/inverse-quantized data. Such modified quantizer may be advantageous for employment in neural networks to compress their data such as feature maps or the like. It may improve accuracy of the neural network.

Abstract: The present disclosure relates to scalable encoding and decoding of pictures. In particular, a picture is processed by one or more network layers of a trained module to obtain base layer features. Then, enhancement layer features are obtained, e.g. by a trained network processing in sample domain. The base layer features are for use in computer vision processing. The base layer features together with enhancement layer features are for use in picture reconstruction, e.g. for human vision. The base layer features and the enhancement layer features are coded in a respective base layer bitstream and an enhancement layer bitstream. Accordingly, a scalable coding is provided which supports computer vision processing and/or picture reconstruction.

Abstract: A method for coding video data is disclosed. The method comprises: obtaining a center motion vector of a coding block; deriving a first motion vector range for the coding block based on the center motion vector and a motion vector spread, wherein the motion vector spread depends on a size of the coding block; if the first motion vector range is at least partially pointing outside a first area including a reference picture, updating the first motion vector range to point within the first area, such that a minimum value or a maximum value of the updated first motion vector range is pointing at a boundary of the first area.

Abstract: A prediction method for an image block comprising a first prediction sub-block and a second prediction sub-block, the prediction method comprising: parsing a first index from a bitstream, wherein the first index is used to obtain prediction information of the first prediction sub-block; parsing a second index from the bitstream; comparing the first index with the second index; adjusting the second index in the event that the second index is equal to or greater than the first index; and obtaining prediction information of the second prediction sub-block according to the adjusted second index.

Abstract: Reference picture management scheme is provided in the context of video coding. A method of decoding an encoded video sequence, comprising obtaining a value of a reference picture list (RPL) syntax element from a bitstream of the encoded video sequence, the RPL syntax element specifying whether syntax elements related to reference picture lists are present in the bitstream, when the RPL syntax element specifies that the syntax elements related to the reference picture lists are present in the bitstream, obtaining, from the bitstream, values of the syntax elements related to the reference picture lists; and constructing at least one reference picture list for inter prediction using the obtained values of the syntax elements related to the reference picture lists.

Abstract: A method for decoding of a video bitstream implemented by a decoding device, wherein the video bitstream includes data representing one or more sequence parameter set, SPS, flags, the method comprising: for an SPS flag of the one or more SPS flags, obtaining two variables of the SPS flag, respectively, by parsing the video bitstream, wherein the value of one variable of the two variables is the minimum allowed value of the SPS flag, and wherein the value of the other variable of the two variables is the maximum allowed value of the SPS flag; obtaining the SPS flag, by parsing the video bitstream; evaluating whether the value of the SPS flag is valid based on the values of the two variables; and in case that the value of the SPS flag is valid, decoding the video bitstream according to the value of the SPS flag.

Abstract: Improved deriving and signaling of minimum and maximum block sizes in the context of partitioning processes is provided herein. In particular, it is provided a method of deriving a minimum coding block size implemented by a decoding device, comprising: parsing a value of a syntax element from a bitstream, deriving the binary logarithm of the minimum coding block size by adding 2 to the parsed value of the syntax element, and deriving the minimum block size from the derived binary logarithm of the minimum coding block size. Restrictions on the syntax element values related to the partitioning process are introduced to prevent undefined behavior and unpredictable code length in case of using variable length codes.

Abstract: The present disclosure relates to methods and apparatuses for encoding video data into a bitstream and for decoding video data received in a bitstream. A second control flag indicating whether or not to use multi-hypothesis prediction for intra and inter mode is generated and transmitted only conditionally, upon a determination whether or not separate merge list technique for subblock merge candidates is used. On the other hand, a decoder is capable of deciding usage of multi-hypothesis prediction for intra and inter mode and separate merge list technique for subblock merge candidates even though the second control flag is transmitted only conditionally.

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 related to adaptive usage of pixel-based and block-based affine motion compensation and includes performing sub-block-based affine transform prediction on an affine block with a first sub-block size if the first sub-block size is greater than or equal to a first sub-block size threshold. If the first sub-block size is less than the first sub-block size threshold, it is determined whether a pixel-based motion vector field is not applied for performing motion compensation for the affine block. If the motion vector field is not applied, a sub-block-based affine motion prediction is performed with a second sub-block size that is based on the first sub-block size. If the pixel-based motion vector field is applied, motion compensation is performed for a sub-block of the affine block using the pixel-based motion vector field.

Abstract: An apparatus for inter prediction of a sample value of a current full-integer pixel of a plurality of pixels associated with a current block of a current frame of a video signal is disclosed. The apparatus is configured to: determine a motion vector of the current full-integer pixel based on a motion compensation model; determine for the current full-integer pixel a corresponding sub-integer pixel in a reference frame; determine positions of a set of corresponding filter support pixels in the reference frame; obtain a respective sample value of the corresponding sub-integer pixel of the current full-integer pixel and the corresponding filter support pixels in the reference frame by applying a bilinear interpolation; and determine the inter predicted sample value of the current full-integer pixel.

Abstract: The present disclosure provides a method of coding implemented by a decoding/encoding device for coding video data. The method comprises the following steps: for a block coded in affine mode, determining control point motion vectors, CPMVs; determining a reference area in a reference picture corresponding to a sub-block of the affine coded block based on the determined CPMVs; setting a variable clipMVX equal to TRUE if a size of the reference area is greater than a predefined threshold, otherwise setting a variable clipMVX equal to FALSE; deriving a pixel-based motion vector field for the affine coded block; wherein, if the variable clipMVX is equal to TRUE, the deriving the pixel-based motion vector field further comprises motion vector clipping based on a first clipping range, wherein the first clipping range is determined based on the determined CPMVs and a size of the affine coded block.

Abstract: A method for inverse quantization of a current block of a picture, the method comprising: receiving a bitstream; obtaining a joint chrominance component residual, JCCR, control flag from the bitstream; obtaining a chrominance mapping information from the bitstream based on the JCCR control flag; obtaining at least one chrominance quantization parameter, QP, offset from the bitstream based on the JCCR control flag; obtaining a QP value for the current chrominance block based on the obtained chrominance mapping information and the at least one obtained chrominance QP offset; performing inverse quantization on the current chrominance block by using the obtained QP value.

Abstract: A method for inverse quantization of a current block of a picture or a frame, where the method is performed by a decoder, and includes obtaining, by a decoder, from a bitstream, a joint chrominance residual (JCCR) mode for a current block of a picture or a frame, obtaining one or more quantization parameter (QP) offset values for chrominance components from the bitstream, determining at least one QP value for the current block depending on the JCCR mode, and performing an inverse quantization process on a chrominance component of the current block using the determined QP value.

Abstract: The present disclosure relates to methods and apparatuses for encoding video data into a bitstream and for decoding video data received in a bitstream. A second control flag indicating whether or not to use multi-hypothesis prediction for intra and inter mode is generated and transmitted only conditionally, upon a determination whether or not separate merge list technique for subblock merge candidates is used. On the other hand, a decoder is capable of deciding usage of multi-hypothesis prediction for intra and inter mode and separate merge list technique for subblock merge candidates even though the second control flag is transmitted only conditionally.

Abstract: A filter is configured for processing a reconstructed frame for generation of a filtered reconstructed frame, and wherein the reconstructed frame comprises a plurality of pixels. The filter includes one or more processor configured to scan a current pixel of the reconstructed block and its neighboring pixels of the current pixel according to a predefined scan template, obtain spectrum components by performing transform for the current pixel and its neighboring pixels, obtain filtered spectrum components based on a filtering parameter and the spectrum components, obtain filtered pixels by performing inverse transform for the filtered spectrum components, and generate a filtered reconstructed block based on the filtered pixels.

Abstract: A method for coding a video implemented in an encoder or a decoder, comprising: determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, according to a preselected affine motion model, the block being an affine block; performing motion compensation for the block using a pixel-based motion vector field according to values of the CPMVs, upon fulfilling at least one of the following conditions: A) for a predefined size of a sub-block of M×M, during processing of one line, respectively, of the sub-block the number of lines of the reference picture is less than N, where N is an integer and N is larger than 2.

Abstract: A method for coding a video implemented in an encoder or a decoder including the enhanced interpolation filter, EIF, for motion compensation, the method comprising: i) determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, the block being an affine block or a sub-block of the affine block; ii) for a predefined sub-block size determining a reference area for a sub-block with the predefined sub-block size according to values of the CPMVs; iii) comparing the determined reference area with a predefined threshold; iv) applying EIF for motion compensation, comprising deriving the pixel-based motion vector field for the block; wherein if the determined reference area is larger than the threshold, deriving the pixel-based motion vector field for the block further comprises motion vector clipping, wherein motion vector clipping range is determined based on motion model of the block and the size of the block.

Abstract: A method for deriving motion information for a current block includes: determining whether the current block and a top neighboring block of the current block are in a same coding tree unit (CTU) or not; obtaining a position of a spatial motion information candidate for the current block; obtaining motion information corresponding to the position of the spatial motion information candidate, depending on the result of whether the current block and top neighboring block of the current block are in the same CTU; adding the obtained motion information to a motion information candidate list for the current block; obtaining a value of a first index of a motion information candidate; and deriving motion information of the current block based on the motion information candidate list and the value of the first index.