(EN) A particular implementation receives geometry data of a 3D mesh, and represents the geometry data with an octree. The particular implementation partitions the octree into three parts, wherein the symbols corresponding to the middle part of the octree are hierarchical entropy encoded. To partition the octree 5 into three parts, different thresholds are used. Depending on whether a symbol associated with a node is an S1 symbol, the child node of the node is included in the middle part or the upper part of the octree. In hierarchical entropy encoding, a non- S1 symbol is first encoded as a pre-determined symbol X using symbol set S2 = {S1, X} and the non-S1 symbol itself is then encoded using symbol set S0 (S0 S1), and an S1 symbol is encoded using symbol set S2. Another implementation defines corresponding hierarchical entropy decoding. A further implementation reconstructs the octree and restores the geometry data of a 3D mesh from the octree representation.
(ZH)
特定实现接收3D网格的几何数据，并利用八叉树表示该几何数据。特定实现将八叉树划分成三个部分，其中分层熵编码与八叉树的中部相对应的符号。为了将八叉树划分成三个部分，使用不同阈值。取决于与节点相联系的符号是否是S1符号，使节点的子节点包括在八叉树的中部或上部中。在分层熵编码中，首先使用符号集S2={S1，X}将非-S1符号编码成预定符号X，然后使用符号集S0![]()
编码非S1-符号本身，以及使用符号集S2编码S1符号。另一种实现定义相应分层熵解码。进一步的实现重构八叉树，并从八叉树表示中恢复3D网格的几何数据。