Image decoding device, image encoding device, and data structure of encoded data

摘要

The present invention reduces the memory needed during decoding. A video decoding device (1) is provided with: a primary direction derivation means (1453A) that consults a prediction mode definition (DEFPM) (1), and from a prediction mode number, derives the primary direction of a prediction direction corresponding to the prediction mode; and a slope derivation unit (1453B) that consults a slope definition table (DEFANG) (1) and derives the slope of the prediction direction.