The present invention relates to an image encoding and decoding technique for a high-definition video compression method and device for an omnidirectional security camera, and more specifically, to a method and a device whereby a differential motion vector is effectively transmitted, and an actual motion vector is calculated using the transmitted differential motion vector, and thus motion compensation is performed.

A system comprises an encoder configured to compress attribute information and/or spatial for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. Additionally, an encoder is configured to signal and/or a decoder is configured to receive a supplementary message comprising volumetric tiling information that maps portions of 2D image representations to objects in the point. In some embodiments, characteristics of the object may additionally be signaled using the supplementary message or additional supplementary messages.

A system comprises an encoder configured to compress attribute information and/or spatial for a point cloud and/or a decoder configured to decompress compressed attribute and/or spatial information for the point cloud. To compress the attribute and/or spatial information, the encoder is configured to convert a point cloud into an image based representation. Also, the decoder is configured to generate a decompressed point cloud based on an image based representation of a point cloud. Additionally, an encoder is configured to signal and/or a decoder is configured to receive a supplementary message comprising volumetric tiling information that maps portions of 2D image representations to objects in the point. In some embodiments, characteristics of the object may additionally be signaled using the supplementary message or additional supplementary messages.

According to the present invention, there is provided A method of encoding a three-dimensional (3D) image, the method comprising: determining a prediction mode for a current block as an inter prediction mode; determining whether a reference block corresponding to the current block in a reference picture has motion information; when the reference block has the motion information, deriving motion information on the current block for each sub prediction block in the current block; and deriving a prediction sample for the current block based on the motion information on the current block.

According to the present invention, there is provided A method of encoding a three-dimensional (3D) image, the method comprising: determining a prediction mode for a current block as an inter prediction mode; determining whether a reference block corresponding to the current block in a reference picture has motion information; when the reference block has the motion information, deriving motion information on the current block for each sub prediction block in the current block; and deriving a prediction sample for the current block based on the motion information on the current block.

A method and device for decoding a point cloud using octree partitioning and a predictive tree include obtaining the point cloud. A bounding box of the point cloud is determined. Octree nodes are generated by partitioning the bounding box using octree partitioning. The predictive tree is generated for points in at least one octree node of the octree nodes. A transform is applied to the predictive tree. The points in the at least one octree node are decoded using the predictive tree.

An apparatus includes a communication interface and a processor operably coupled to the communication interface. The communication interface receives a plurality of tracks in a compressed bitstream. The processor identifies an atlas track corresponding to a point cloud compression (PCC) component and identifies a set of first component tracks that is referenced by the atlas track and at least one second component track, each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The processor also determines which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component. The processor further decodes the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track.

An apparatus includes a communication interface and a processor operably coupled to the communication interface. The communication interface receives a plurality of tracks in a compressed bitstream. The processor identifies an atlas track corresponding to a point cloud compression (PCC) component and identifies a set of first component tracks that is referenced by the atlas track and at least one second component track, each of the at least one second component track is an alternative version of a first component track of the set of first component tracks. The processor also determines which of the set of first component tracks and the at least one second component track are appropriate versions of the PCC component. The processor further decodes the appropriate version of the PCC component from among the set of first component tracks and the at least one second component track.

Aspects of the disclosure include a method for point cloud coding. In the method, whether decoding of occupancy codes of nodes in a range of octree partition depths in an octree partitioning structure of a point cloud reaches a minimum octree partition depth at which parallel decoding is enabled is determined. Arithmetic coding information for decoding the occupancy codes of the nodes in the minimum octree partition depth is stored based on the decoding of the occupancy codes of the nodes in the range of octree partition depths reaching the minimum octree partition depth. The parallel decoding is performed on occupancy codes of the nodes in each of the at least one remaining octree partitions depth based on the stored arithmetic coding information. The point cloud is reconstructed based on the occupancy codes of the nodes in the range of octree partition depths in the octree partitioning structure.

Aspects of the disclosure include a method for point cloud coding. In the method, whether decoding of occupancy codes of nodes in a range of octree partition depths in an octree partitioning structure of a point cloud reaches a minimum octree partition depth at which parallel decoding is enabled is determined. Arithmetic coding information for decoding the occupancy codes of the nodes in the minimum octree partition depth is stored based on the decoding of the occupancy codes of the nodes in the range of octree partition depths reaching the minimum octree partition depth. The parallel decoding is performed on occupancy codes of the nodes in each of the at least one remaining octree partitions depth based on the stored arithmetic coding information. The point cloud is reconstructed based on the occupancy codes of the nodes in the range of octree partition depths in the octree partitioning structure.