Image coding method, image decoding method, image coding apparatus, image decoding apparatus, and image coding and decoding apparatus

摘要

An image coding method includes: a subtraction step of generating for each coding unit (CU) a predicted error signal (111) by subtracting a prediction signal (181) from an input image signal (101); a transformation quantisation step of, for each transformation unit (TU), orthogonal transformation of the predicted error signal (111) and generation of a quantisation coefficient (131) at each quantisation; and a coding step of coding in a single tree structure the management information and quantisation coefficients (131) indicating the structure of the plurality of transformation units (TU). The respective plurality of transformation units (TU) correspond respectively to the leaf nodes of the tree structure. In the coding step, for each leaf node, a code signal (191) is generated that is obtained by coding the management information and quantisation coefficient (131) corresponding to the leaf node in question and arranging the coded management information and coded quantisation coefficient in a single entity.