SIGNIFICANT MAP DECODING DEVICE AND METHOD, DECODER, PREDICTION DECODER, CONVERSION COEFFICIENT BLOCK DECODING DEVICE AND METHOD, SIGNIFICANT MAP ENCODING DEVICE AND METHOD, COMPUTER PROGRAM, AND COMPUTER READABLE DIGITAL STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To efficiently encode a significant map showing the position of a significant conversion coefficient in a conversion coefficient block.SOLUTION: When extracting a significant map and a value of a significant conversion coefficient from a data stream in decoding of the significant map from the data stream, a first type syntax element is sequentially extracted from the data stream with context adaptive entropy decoding. The first type syntax element shows whether a significant or insignificant conversion coefficient is arranged on a relevant position in a conversion coefficient block. When performing context adaptive entropy decoding to the first type syntax element, contexts are used, the contexts being individually selected in accordance with many positions in which significant conversion coefficients are arranged on the basis of previously extracted and associated first type syntax elements in the neighboring part of the position with which the current first type syntax element is associated.