The disclosure proposes a decoder for decoding coefficients of blocks of a video sequence from a bitstream. The decoder comprises a scan pattern list module for providing one or more pre-defined scan orders, a scan order generator for generating one or more scan orders, a scan order selector for selecting a scan order for each block from the pre-defined and generated scan orders on the basis of scan order information contained in the bitstream, a decoding module for decoding one or more coefficient vectors of each block from the bitstream, a deserializer for inverse scanning, for each block, the one or more coefficient vectors of that block according to the scan order selected for that block so as to obtain a coefficient matrix. The scan order generator generates the one or more scan orders depending on one or more previously obtained coefficient matrices of blocks of the video sequence.

An apparatus for point cloud decoding includes processing circuitry. The processing circuitry receives, from a coded bitstream for a point cloud, encoded occupancy codes for nodes in an octree structure for the point cloud. The nodes in the octree structure correspond to three dimensional (3D) partitions of a space of the point cloud. Sizes of the nodes are associated with sizes of the corresponding 3D partitions. Further, the processing circuitry decodes, from the encoded occupancy codes, occupancy codes for the nodes. At least a first occupancy code for a child node of a first node is decoded without waiting for a decoding of a second occupancy code for a second node having a same node size as the first node. Then, the processing circuitry reconstructs the octree structure based on the decoded occupancy codes for the nodes, and reconstructs the point cloud based on the octree structure.

An apparatus for point cloud decoding includes processing circuitry. The processing circuitry receives, from a coded bitstream for a point cloud, encoded occupancy codes for nodes in an octree structure for the point cloud. The nodes in the octree structure correspond to three dimensional (3D) partitions of a space of the point cloud. Sizes of the nodes are associated with sizes of the corresponding 3D partitions. Further, the processing circuitry decodes, from the encoded occupancy codes, occupancy codes for the nodes. At least a first occupancy code for a child node of a first node is decoded without waiting for a decoding of a second occupancy code for a second node having a same node size as the first node. Then, the processing circuitry reconstructs the octree structure based on the decoded occupancy codes for the nodes, and reconstructs the point cloud based on the octree structure.

The present disclosure provides a method and an apparatus for determining an intra-frame prediction mode of a current video block. The method includes determining, in an image area including a to-be-coded current video block, reference modes of the current video block based on a plurality of intra-frame prediction modes of a plurality of second video blocks, the image area being in an area defined by an adjacent coding unit (CU) and a father CU corresponding to the current video block in a video frame or slice including the current video block; determining an alternative prediction mode set from preset intra-frame prediction modes, the alternative prediction mode set comprising a plurality of alternative prediction modes, including the reference modes; and determining, in the alternative prediction mode set, a prediction mode having optimal intra-frame prediction coding performance on the current video block as an intra-frame prediction mode of the current video block.

Provided is a video decoding method of applying a deblocking filter to neighboring pixels adjacent to a boundary of a current block, the video decoding method including selecting a deblocking filter to be applied to the neighboring pixels from among a plurality of deblocking filters according to pixel values of the neighboring pixels and a size of the current block, and applying the selected deblocking filter to the neighboring pixels, wherein the plurality of deblocking filters include three or more deblocking filters having different ranges of neighboring pixels to which deblocking filtering is applied.

An apparatus for processing a video may receive a quantization parameter (QP) adjustment value associated with a syntax level at the syntax level. In examples, the apparatus may obtain the QP adjustment value associated with the syntax level, for example, via signalling at the syntax level. The apparatus may apply the QP adjustment value to a QP associated with the syntax level to obtain an adjusted QP associated with the syntax level. The syntax level may include a coding block level or a transform unit (TU) level. In examples, if the syntax level is a TU level, the decoder may receive the QP adjustment value for a first CU (for example, a current TU) and obtain a QP for the second TU that precedes the first CU in a coding order based on a QP predictor, for example, instead of the QP adjustment value for the first TU.

An apparatus for processing a video may receive a quantization parameter (QP) adjustment value associated with a syntax level at the syntax level. In examples, the apparatus may obtain the QP adjustment value associated with the syntax level, for example, via signalling at the syntax level. The apparatus may apply the QP adjustment value to a QP associated with the syntax level to obtain an adjusted QP associated with the syntax level. The syntax level may include a coding block level or a transform unit (TU) level. In examples, if the syntax level is a TU level, the decoder may receive the QP adjustment value for a first CU (for example, a current TU) and obtain a QP for the second TU that precedes the first CU in a coding order based on a QP predictor, for example, instead of the QP adjustment value for the first TU.

A method of decoding a coding unit from a coding tree unit of an image frame from a video bitstream. The method comprises determining a scan pattern for a transform block the scan pattern progressing from a current collection to a next collection of the plurality of collections after completing scanning of the current collection; decoding residual coefficients from the video bitstream according to the scan pattern; determining a multiple transform selection index for the coding unit, decoding the multiple transform selection index from the video bitstream if a last significant coefficient encountered along the scan pattern is at or within a threshold cartesian location of the transform block, and determining the multiple transform selection index to indicate that multiple transform selection is not used if the last significant residual coefficient position of the transform block along the scan pattern outside the threshold location; and transforming the decoded residual coefficients.

A method of decoding a coding unit from a coding tree unit of an image frame from a video bitstream. The method comprises determining a scan pattern for a transform block the scan pattern progressing from a current collection to a next collection of the plurality of collections after completing scanning of the current collection; decoding residual coefficients from the video bitstream according to the scan pattern; determining a multiple transform selection index for the coding unit, decoding the multiple transform selection index from the video bitstream if a last significant coefficient encountered along the scan pattern is at or within a threshold cartesian location of the transform block, and determining the multiple transform selection index to indicate that multiple transform selection is not used if the last significant residual coefficient position of the transform block along the scan pattern outside the threshold location; and transforming the decoded residual coefficients.

The present disclosure relates to an image processing apparatus and method capable of suppressing an increase in load of inverse adaptive color transform processing while suppressing an increase in distortion of coefficient data subjected to inverse adaptive color transform.

The coefficient data subjected to the lossless adaptive color transform is clipped at a level based on a bit depth of the coefficient data, and the coefficient data clipped at the level is subjected to lossless inverse adaptive color transform. The present disclosure may be applied to, for example, an image processing apparatus, an image coding device, an image decoding device, a transmission device, a reception device, a transmission/reception device, an information processing device, an imaging device, a reproduction device, an electronic device, an image processing method, an information processing method, or the like.