Abstract: A method of coding at least one image sliced into blocks. The method implements, for a current block to be coded: predicting the current block in accordance with a prediction mode selected from among predetermined prediction modes, Intra and Inter, the selected mode of prediction being Intra; calculating a residual data block representative of a difference between a predictor block obtained on completion of the prediction and the current block; applying a transform operation to the data of the residual block, the transform operation belonging to a set of transform operations previously stored in association with the selected mode of Intra prediction; and coding the data obtained from the transform operation. The number of transform operations contained in the set associated with the selected Intra mode is different from the number of transform operations contained in a set of transform operations stored in association with the mode of Inter prediction.

Abstract: Systems, apparatus, articles, and methods are described including operations for size based transform unit context derivation.

Abstract: Methods, processes, and systems are presented for adaptive loop filtering in coding and decoding high dynamic range (HDR) video. Given an input image block, its luminance information may be used to adapt one or more parameters of adaptive loop filtering and compute gradient and directionality information, activity information, a classification index, and adaptive-loop-filtering coefficients.

Abstract: An apparatus includes a memory and a processor. The processor is configured to execute instructions stored in the memory to obtain a transform type for decoding a transform block for the current block; select, based on the transform type, a template for coding a value of a non-zero map; select, based on the template, a context for entropy decoding the value of the non-zero map; and decode the value of the non-zero map based on the context. The non-zero map indicates which coefficients of the transform block have non-zero values. A method includes obtaining a transform class for coding a transform block for the current block, wherein the transform class corresponding to a transform type and a direction; selecting, based on the transform class, a coding context for coding a value of a non-zero map; and coding the value of the non-zero map based on the coding context.

Abstract: According to the present invention, an image-encoding method comprises the following steps: receiving image information; generating a restored block for the current block based on the image information; and generating a finally restored block for the current block by applying an in-loop filter to the restored block on the basis of the image information. According to the present invention, image-encoding/decoding efficiency may be improved.

Abstract: The present invention avoids waste caused by performing both a Secondary Transform and an Adaptive Multiple Core Transform. Provided is a device including: a core transform unit (1521) that can perform an Adaptive Multiple Core Transform on a Coding Tree Unit; and a Secondary Transform unit (1522) that can perform, before the Adaptive Multiple Core Transform, a Secondary Transform on at least any one of sub-blocks included in the Coding Tree Unit. The device omits any of the Adaptive Multiple Core Transform and the Secondary Transform in accordance with at least any of a flag associated with the Adaptive Multiple Core Transform and a flag associated with the Secondary Transform, or in accordance with a size of the Coding Tree Unit.

Abstract: A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Abstract: Disclosed is a method of decoding residual coefficients of a transform unit from a bitstream of video data. The method receives the transform unit (1500) from the bitstream of video data in which the transform unit has upper (1503) and lower (1502) level square layers. The upper level layer represents a square arrangement of at most four significant coefficient group flags with each of the significant coefficient group flags representing a non-overlapping region of the lower level layer. The method determines determining the significant coefficient group flags of the square upper level layer for the received transform unit, and determines values of residual coefficients of the square lower layer according to the determined significant coefficient group flags to decode the transform unit of the bitstream of video data. Corresponding encoding methods are also disclosed.

Abstract: This quantization device includes a processor configured to calculate first costs in a plurality of data length candidates in consideration of the compression ratio and image quality deterioration due to compression of an image. The cost calculation processing is common processing partially performed among the plurality of data length candidates. The processor is configured to perform the common processing for the plurality of data length candidates, execute the distributed processes in parallel, and determine, as an optimal data length, a single data length for which a minimum cost is calculated among the first costs of the plurality of data length candidate.

Abstract: A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode.

Abstract: Aspects of the disclosure provide methods and apparatuses for video coding. In the method, a bit stream including syntax elements is received. The syntax elements correspond to residues of a transform block in a coded picture. A first maximum number of context-coded bins of the syntax elements of a first coefficient sub-block in the transform block is determined based on a frequency position of the first coefficient sub-block. Each of a number of bins of the syntax elements of the first coefficient sub-block is coded according to a context model and the determined first maximum number. Coded bits of the number of the bins of the syntax elements of the first coefficient sub-block are decoded based on the context models. Further, the first maximum number is different from a second maximum number of context-coded bins of the syntax elements of a second coefficient sub-block in the transform block.

Abstract: Methods, devices and apparatus for reconstructing an image are provided. According to an example of the method, scanning data is obtained for a scanned subject, an initially-updated image is reconstructed from the scanning data, image boundary prior information is generated by performing at least two sparse transforms on the initially-updated image, and a reconstructed image is obtained by performing a weighted reconstruction with the image boundary prior information and the initially-updated image.

Abstract: A method for decoding an encoded video bit stream in a video decoder is provided that includes determining a scan pattern type for a transform block to be decoded, decoding a column position X and a row position Y of a last non-zero coefficient in the transform block from the encoded video bit stream, selecting a column-row inverse transform order when the scan pattern type is a first type, selecting a row-column inverse transform order when the scan pattern type is a second type, and performing one dimensional (1D) inverse discrete cosine transformation (IDCT) computations according to the selected transform order to inversely transform the transform block to generate a residual block.

Abstract: A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode.

Abstract: A picture defined in video data is partitioned into blocks that include a luminance (luma) transform block and a chrominance (chroma) transform block. One or more constraints pertaining to the picture are determined from high-level syntax elements and transform skipping of one of both of the luma transform block and the chroma transform block is disallowed if the constraints are not met. The video data are encoded in a bitstream along with an indication that the transform of the luma transform block or the chroma transform block is skipped in response to the transform being skipped.

Abstract: The present invention provides a method for encoding a video signal on the basis of a graph-based lifting transform (GBLT), comprising the steps of: detecting an edge from an intra residual signal; generating a graph on the basis of the detected edge, wherein the graph includes a node and a weight link; acquiring a GBLT coefficient by performing the GBLT for the graph; quantizing the GBLT coefficient; and entropy-encoding the quantized GBLT coefficient, wherein the GBLT includes a partitioning step, a prediction step, and an update step.

Abstract: Apparatuses and methods are disclosed for adapting scan order of a transform block. An apparatus for decoding coefficients of a transform block includes a processor. The processor is configured to decode, from a compressed bitstream, first coefficients of at least one row of the transform block; decode, from the compressed bitstream, second coefficients of at least one column of the transform block, where the transform block consists of the first coefficients, the second coefficients, and remaining coefficients; select, using the first coefficients and the second coefficients, a scan order for decoding the remaining coefficients; and decode the remaining coefficients of the transform block using the scan order.

Abstract: A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Abstract: A processing system may obtain a first frame of a first variant associated with a reference copy of a video, where a plurality of variants comprises copies of the video encoded at different bitrates, determine a frame number of the first frame from a visual overlay containing the first frame number, calculate a first image distance between the first frame and a frame of the reference copy having the frame number, determine, from among a plurality of image distances for frames of each variant having the frame number, a closest image distance to the first image distance, the plurality of image distances comprising image distances between frames of the variants and the frame of the reference copy having the frame number, and identify the first frame as being from the first variant in accordance with a variant associated with the first closest image distance.

Abstract: Delta quantized coefficients of a pixel block in a picture in a first representation of a video sequence are encoded based on information derived from estimated quantized coefficients for the pixel block. The delta quantized coefficients represent a difference between actual quantized coefficients of the pixel block derived by encoding at least a portion of the picture in the first representation of the video sequence and the estimated quantized coefficients. The estimated quantized coefficients represent a difference between a reconstructed block of a corresponding picture in a second representation of the video sequence and a prediction block obtained based on intra mode information and/or inter motion information derived by encoding the picture in the first representation of the video sequence.

Abstract: A transform block processing procedure wherein a maximum coding-block size and a maximum transform-block size for an unencoded video frame is determined. The unencoded video frame is divided into a plurality of coding-blocks including a first coding-block and the first coding block is divided into at least one prediction block and a plurality of transform blocks. The size of the transform blocks depend at least in part on the size of the coding block and the corresponding prediction blocks. The transform blocks are then encoded, thereby generating a video data payload of an encoded bit-stream. A frame header of the encoded bit-stream, including a maximum coding-block size flag and a maximum-transform-block-size flag, is generated.

Abstract: A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Abstract: There is provided an image processing apparatus and method that make it possible to suppress reduction of the encoding efficiency. Encoded data is decoded, and based on a value of a transform skip identifier obtained by the decoding, execution of an inverse primary vertical transform and execution of an inverse primary horizontal transform are controlled. Further, based on a value of a transform skip identifier, execution of a primary horizontal transform and execution of a primary vertical transform are controlled, and the transform skip identifier is encoded. The present disclosure can be applied, for example, to an image processing apparatus, an image encoding apparatus, an image decoding apparatus or the like.

Abstract: Methods, processes, and systems are presented for adaptive loop filtering in coding and decoding high dynamic range (HDR) video. Given an input image block, its luminance information may be used to adapt one or more parameters of adaptive loop filtering and compute gradient and directionality information, activity information, a classification index, and adaptive-loop-filtering coefficients.

Abstract: A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode.

Abstract: The present invention provides a method for encoding a video signal by using a single optimized graph, comprising the steps of: obtaining a residual block; generating graphs from the residual block; generating an optimized graph and an optimized transform by combining the graphs, wherein the graphs are combined on the basis of an optimization step; and performing a transform for the residual block on the basis of the optimized graph and the optimized transform.

Abstract: A method is provided for coding at least one image split up into partitions, a current partition to be coded containing data, at least one data item of which is allotted a sign. The coding method includes, for the current partition, the following steps: calculating the value of a function representative of the data of the current partition with the exclusion of the sign; comparing the calculated value with a predetermined value of the sign; as a function of the result of the comparison, modifying or not modifying at least one of the data items of the current partition, in the case of modification, coding the at least one modified data item.

Abstract: Methods and apparatus are provided for improved entropy encoding and decoding. An apparatus includes a video encoder (200) for encoding at least a block in a picture by transforming a residue of the block to obtain transform coefficients, quantizing the transform coefficients to obtain quantized transform coefficients, and entropy coding the quantized transform coefficients. The quantized transform coefficients are encoded using a flag to indicate that a current one of the quantized transform coefficients being processed is a last non-zero coefficient for the block having a value greater than or equal to a specified value.

Abstract: A decoding device, including circuitry configured to decode a bit stream and generate a quantized value, and inversely quantize the generated quantized value by using a flat scaling list, in a case where a block size of a transform block to which a transform skip is applied is larger than a 4 by 4 block size.

Abstract: A method for encoding an image having been cut up into partitions. The method includes: predicting data of a current partition based on an already encoded and then decoded reference partition, generating a predicted partition; determining residual data by comparing data relating to the current partition with the predicted partition, the residual data associated with various digital data items. Prior producing a signal containing the encoded information, performing the following steps: determining, from the predetermined residual data, a subset containing residual data capable of being modified; calculating the value of a function representative of the residual data; comparing the calculated value with a value of at least one of the digital data items; based on the comparison, modification or non-modification of at least one of the residual data items of the subset; and, in the event of a modification, entropy encoding the at least one modified residual data item.

Abstract: The present disclosure relates to a still image generating apparatus that generates still image data from moving image data that generates a moving image, and includes a recorder and a control unit. The recorder is configured to record the still image data. When a specific frame image is selected from a plurality of frame images included in the moving image, the control unit sets a specific frame image group including the specific frame image and other frame images having a reference relationship with the specific frame image. The control unit generates the still image data corresponding to each of the plurality of frame images included in the specific frame image group by decoding the moving image data. The control unit causes the recorder to record the generated still image data. The control unit generates frame image data that generates at least one of the plurality of frame images included in the specific frame image group based on the still image data recorded by the recorder.

Abstract: Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. If there are no non-zero significant-coefficient flags in the group, then the significant-coefficient-group flag is set to zero. The set of significant-coefficient-group flags is encoded in the bitstream. Any significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is non-zero are encoded in the bitstream, whereas significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is zero are not encoded in the bitstream.

Abstract: While maintaining a high degree of freedom in choosing partition sizes and transformation sizes adapted for local characteristics of videos, the amount of metadata is decreased. A video encoding apparatus (10) divides an input video into blocks of a prescribed size and encodes the video block by block. The video encoding apparatus is provided with: a prediction parameter determining portion (102) that decides the block partition structure; a predictive image producing portion (103) that generates predictive images, partition by partition, as prescribed by the partition structure; a transform coefficient producing portion (107) which applies one of the frequency transformations included in a prescribed transformation preset to prediction residuals, i.e. the differences between predictive images and the input video; a transform restriction deriving portion (104) which generates the list of transform candidate, i.e.

Abstract: A method including writing of kernel modules to process Magnetic Resonance (MR) data acquired from MRI Scanner using a parallel implementation of Magnetic Resonance Fingerprinting (MRF) algorithm on a parallel architecture; and launching multiple threads simultaneously.

Abstract: Several methods and systems for reducing blocking artifacts are disclosed. In an embodiment, the method includes receiving a pair of adjacent blocks having an edge being positioned between the adjacent blocks. The pair of adjacent blocks is associated with one or more coding blocks. The one or more coding blocks comprise one or more coding information associated with the coding of the pair of adjacent blocks. The method also includes conducting a determination of whether the pair of adjacent blocks is coded in a skip-mode based on the one or more coding information. The edge is filtered based on the determination. Filtering the edge comprises disabling a de-blocking filtering of the edge based on a determination that the pair of adjacent blocks is coded in the skip-mode; and enabling the de-blocking filtering of the edge based on determination that the pair of adjacent blocks is not associated with the skip-mode.

Abstract: A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode.

Abstract: A method for luma-based chroma intra-prediction in a video encoder or a video decoder is provided that includes down sampling a first reconstructed luma block of a largest coding unit (LCU), computing parameters ? and ? of a linear model using immediate top neighboring reconstructed luma samples and left neighboring reconstructed luma samples of the first reconstructed luma block and reconstructed neighboring chroma samples of a chroma block corresponding to the first reconstructed luma block, wherein the linear model is PredC[x,y]=?·RecL?[x,y]+?, wherein x and y are sample coordinates, PredC is predicted chroma samples, and RecL? is samples of the down sampled first reconstructed luma block, and wherein the immediate top neighboring reconstructed luma samples are the only top neighboring reconstructed luma samples used, and computing samples of a first predicted chroma block from corresponding samples of the down sampled first reconstructed luma block using the linear model and the parameters.

Abstract: In an example, an electronic device of a decoder is configured to obtain a bit stream and recover a binary symbol from the obtained bit stream. The electronic device is configured to determine whether the binary symbol is to be decoded using a modified transform skip mode. The electronic device is configured to, in response to determining that the binary symbol is not to be decoded using the modified transform skip mode, determine a first TS_Shift value, and recover video data using the first TS_Shift value. The electronic device is configured to, in response to determining that the binary symbol is to be decoded using the modified transform skip mode, determine a second TS_Shift value, and recover video data using the second TS_Shift value.

Abstract: A video coder, such as a video encoder or a video decoder, uses a first Rice parameter derivation method and a second Rice parameter derivation method for coding coefficient levels of the TU. The first Rice parameter derivation method is a statistics-based derivation method. The second Rice parameter derivation method is a template-based derivation method.

Abstract: A method of video decoding for a video decoder includes determining whether a block size of a chroma block is less than or equal to a block size threshold. The method further includes, in response to a determination that the block size of the chroma block is greater than the block size threshold, selecting an intra prediction mode for the chroma block from a plurality of intra prediction modes. The method further includes, in response to a determination that the block size of the chroma block is less than or equal to the block size threshold, selecting the intra prediction mode for the chroma block from a subset of the plurality of intra prediction modes. The method further includes performing intra prediction for the chroma block based on a chroma sample obtained with the selected intra prediction mode.

Abstract: A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Abstract: Techniques are described that enable a two-dimensional (2D) representation of three-dimensional (3D) virtual reality (VR) content to be encoded. These techniques include encoding VR content while excluding non-display pixels of the VR content from motion estimation during encoder processing.

Abstract: A method for video decoding includes determining, for a current block that is a non-square block, whether an angular intra prediction mode for the current block is a wide angle mode that is in a direction outside of a range of directions that spans a bottom left diagonal direction and top right diagonal direction of the current block. The method further includes, in response to determining that the angular intra prediction mode is the wide angle mode, determining whether a condition to apply an intra smoothing filter to blocks neighboring the current block is satisfied. The method further includes, in response to determining that the condition is satisfied, applying the intra smoothing filter to the blocks neighboring the current block. The method also includes performing intra prediction based on the filtered blocks to obtain a characteristic value for the current block.

Abstract: A method of decoding video data comprises receiving a bitstream of encoded video data, the encoded video data representing partitioned luma blocks and partitioned chroma blocks, wherein the chroma blocks are partitioned independently of the luma blocks, determining a respective coding mode corresponding to the respective partitioned luma blocks, decoding the respective partitioned luma blocks according to the determined respective coding modes, decoding a first syntax element indicating that the respective coding modes associated with the respective partitioned luma blocks are to be used for decoding a first partitioned chroma block, wherein the first partitioned chroma block is aligned with two or more partitioned luma blocks, determining a chroma coding mode for the first partitioned chroma block according to a function of the respective coding modes of the two or more partitioned luma blocks, and decoding the first partitioned chroma block in accordance with the determined chroma coding mode.

Abstract: Provided is a method for decoding a video signal. The method includes generating a first prediction sample by performing intra prediction on a current block, determining an intra prediction pattern of a current block, partitioning the current block into a plurality of sub-blocks based on the determined intra prediction pattern, generating a first prediction sample for a sub-block by performing intra prediction, determining an offset for the sub-block to obtain a second prediction sample, and generating the second prediction sample for the sub-block by using the first prediction sample and the offset.

Abstract: A method of decoding JVET video includes receiving a bitstream indicating how a coding tree unit was partitioned into coding units, and parsing said bitstream to generate at least one predictor based on an intra prediction mode signaled in the bitstream. The predictor may be generated by interpolating neighboring pixels for each pixel within a coding block. The computation may be more accurate by deriving a value for a bottom right neighboring pixel.

Abstract: Disclosed is a method of decoding residual coefficients of a transform unit from a bitstream of video data. The method receives the transform unit (1500) from the bitstream of video data in which the transform unit has upper (1503) and lower (1502) level square layers. The upper level layer represents a square arrangement of at most four significant coefficient group flags with each of the significant coefficient group flags representing a non-overlapping region of the lower level layer. The method determines determining the significant coefficient group flags of the square upper level layer for the received transform unit, and determines values of residual coefficients of the square lower layer according to the determined significant coefficient group flags to decode the transform unit of the bitstream of video data. Corresponding encoding methods are also disclosed.

Abstract: Techniques include signaling information used to generate three-dimensional (3D) color lookup tables for color gamut scalability in multi-layer video coding. A lower layer of video data may include color data in a first color gamut and a higher layer of the video data may include color data in a second color gamut. To generate inter-layer reference pictures, a video encoder and/or video decoder performs color prediction to convert the color data of a reference picture in the first color gamut to the second color gamut. The video coder may perform color prediction using a 3D lookup table. According to the techniques, a video encoder may encode partition information and/or color values of a 3D lookup table generated for color gamut scalability. A video decoder may decode the partition information and/or color values to generate the 3D lookup table in order to perform color gamut scalability.

Abstract: Disclosed is a method of decoding residual coefficients of a transform unit from a bitstream of video data. The method receives the transform unit (1500) from the bitstream of video data in which the transform unit has upper (1503) and lower (1502) level square layers. The upper level layer represents a square arrangement of at most four significant coefficient group flags with each of the significant coefficient group flags representing a non-overlapping region of the lower level layer. The method determines determining the significant coefficient group flags of the square upper level layer for the received transform unit, and determines values of residual coefficients of the square lower layer according to the determined significant coefficient group flags to decode the transform unit of the bitstream of video data. Corresponding encoding methods are also disclosed.

Abstract: Generating a new scan order includes incrementing a next index value after assigning the next index value to a coefficient in the new scan order; assigning, to a first coefficient at a first scan index m in the original scan order, a first scan index in the new scan order, the first coefficient is a context coefficient for entropy coding a parent coefficient that is at a parent scan index n in the original scan order; adding, to a list, a first item indicative of the parent coefficient and parent scan index n; before assigning a second scan index to a second coefficient that is at a second index m+j in the original scan order, wherein j>1, assigning the next index value to the parent coefficient, and removing the first item from the list; and assigning the next index value to the second coefficient in the new scan order.