Efficient labeling procedures for image partition encoding. (Q1575370)

A new approach to the lossless encoding of an image partition is presented. The segmented image is first described by a quadtree, whose leaves are then grouped by a labeling procedure to represent any configuration. Label assignment exploits the `four colors' theorem, thus allowing each label with 2 bits to be encoded. A simple and efficient label assignment algorithm is also proposed which further reduces the code entropy. The proposed representation is an effective alternative to region- and edge-based partition encoders used in II generation image coders.