| CPC H04N 19/44 (2014.11) [H04N 19/105 (2014.11); H04N 19/117 (2014.11); H04N 19/119 (2014.11); H04N 19/176 (2014.11); H04N 19/82 (2014.11); H04N 19/96 (2014.11)] | 8 Claims |
|
1. A video decoding method for decoding a bitstream containing an encoded sequence of pictures which are partitioned into a plurality of subpictures including a plurality of coding tree blocks, the method comprising:
decoding, from the bitstream, information on a coding tree block size and layout information about the subpictures which are partitioned from the pictures included in the sequence;
splitting, in a tree structure, a to-be-decoded coding tree block among the coding tree blocks which have the coding tree block size in any one of the subpictures identified by the layout information, and determining a target block;
decoding, from the bitstream, prediction information for predicting the target block and information about residual signals of the target block;
predicting pixels in the target block based on the prediction information and generating a prediction block;
generating a residual block for the target block based on information about the residual signals;
reconstructing the target block by adding the prediction block and the residual block; and
performing loop filtering on a target pixel to be filtered in the reconstructed target block by applying filter coefficients to the target pixel and neighboring pixels of the target pixel,
wherein, when at least one of the neighboring pixels is outside the boundary of a subpicture including the target block, the loop filtering is performed on the target pixel based on an alternative pixel in place of the at least one of the neighboring pixels,
wherein, the alternative pixel is a pixel in the subpicture which is adjacent to the boundary of the subpicture,
wherein, the layout information includes a number of the subpictures, identification information for identifying a position of a first coding tree block in a raster scan order within each of the subpictures, and information about subpicture sizes,
wherein, the identification information is information for identifying a position of a coding tree block located at a top left in each of the subpictures,
wherein, the information about the subpicture sizes includes a width of each of the subpictures in units of coding tree block size, which is determined by the information on the coding tree block size, and a height of each of the subpictures in units of coding tree block size,
wherein, widths of the subpictures are identified using the information on the coding tree block size and the width of each of the subpictures in units of coding tree block size and heights of the subpictures are identified using the information on the coding tree block size and the height of each of the subpictures in units of coding tree block size,
wherein ID information indicating a parameter set related to the loop filtering is decoded from a header of a slice containing the target block positioned therein,
wherein one or more filter coefficient sets for the loop filtering of blocks in the slice are reconstructed from the parameter set corresponding to the ID information decoded from the header of the slice,
wherein a filter coefficient set to be used for the to-be-decoded coding tree block including the target block is selected either from the one or more filter coefficient sets reconstructed from the parameter set or from pre-defined filter coefficient sets, based on information about filter sets applied to coding tree block, and
wherein the loop filtering on the target pixel is performed using the filter coefficients in the selected filter coefficient set for the to-be-decoded coding tree block.
|