This invention discloses a dual-
stream point cloud compression method and
system based on semantic scene graphs, relating to the field of
point cloud compression. It constructs a
point cloud compression network comprising an
encoder network and a decoder network: In the
encoder network, semantic labels are mapped onto the input point cloud, and scene graphs and
octree representations are constructed respectively. Semantic modulation parameters are generated based on the
scene graph and encoded to obtain a semantic
bitstream. The
octree representation, under the influence of semantic modulation parameters, undergoes feature enhancement and attention probability prediction to obtain node occupancy probabilities, and a geometric
bitstream is generated through arithmetic encoding. These two bitstreams serve as compressed data. In the decoder network, the bitstreams are decoded, and the
octree structure and
scene graph information are reconstructed. Node feature representations are recovered by combining the semantic modulation parameters. The reconstructed octree structure is mapped back to the point cloud space through spatial querying and indexing to reconstruct the point cloud. This invention solves the problem of local
geometric distortion in low-bitrate octree point cloud compression, ensuring reconstruction quality while reducing the transmission bitrate.