JVET quadtree plus binary tree (QTBT) structure with multiple asymmetrical partitioning
A method of partitioning in video coding for JVET, comprising representing a JVET coding tree unit as a root node in a quadtree plus binary tree (QTBT) structure that can have quadtree or binary partitioning of the root node and quadtree or binary trees branching from each of the leaf nodes. The partitioning at any depth can use asymmetric binary partitioning to split a node represented by a leaf node into two child nodes of unequal size, representing the two child nodes as leaf nodes in a binary tree branching from the parent leaf node and coding the child nodes represented by final leaf nodes of the binary tree with JVET, wherein further partitioning of child nodes split from leaf nodes via asymmetric binary partitioning is allowed recursively along the same branch in any order with symmetric partitioning.
1. A method of decoding a bitstream, the method comprising:
(a) receiving a bitstream indicating how a coding tree unit was partitioned into coding units according to a partitioning structure that allows a node to be split with at least one of quaternary tree partitioning, symmetric binary tree partitioning, and/or asymmetric tree partitioning;
(b) parsing said bitstream to determine if at least one of asymmetric tree partitioning and/or symmetric binary tree partitioning splits a parent node into child nodes, wherein symmetric binary tree partitioning splits a parent node into a plurality of child nodes of equal size, and asymmetric tree partitioning splits a parent node into a plurality of child nodes of unequal size;
(c) identifying each of the child nodes within each respective parent node, wherein a node can be recursively partitioned into smaller nodes;
(d) wherein the partitioning structure allows both asymmetric tree partitioning and symmetric binary tree partitioning to occur in either order during recursive partitioning;
(e) wherein the partitioning structure allows further partitioning of child nodes that are produced from asymmetric tree partitioning of at least one parent node; and
(f) decoding the identified coding units using an intra decoding process.
2. The method of claim 1 , wherein said asymmetric tree partitioning produces child nodes having a size ratio that is anything other than 1.
3. The method of claim 2 , wherein at least one node is asymmetrically partitioned including two child nodes of unequal sizes, where a larger child node is three times as large as a smaller child node for a size ratio of 3:1.
4. The method of claim 2 , wherein at least one node is asymmetrically partitioned including two child nodes of unequal sizes, where a larger child node is two times as large as a smaller child node for a size ratio of 2:1.