Image encoding apparatus and image decoding apparatus employing intra preciction and direction transform matrix

Abstract

An image encoding apparatus includes a setting unit configured to set a combination of a vertical transform matrix and a horizontal transform matrix corresponding to the target image. The combination includes any of a plurality of transform matrices including a first transform matrix and a second transform matrix which increases a coefficient density compared to the first transform matrix if a one-dimensional orthogonal transformation in a direction orthogonal to a line of a group of reference pixels on at least one line is performed on the prediction error in the intra-prediction mode in which the group of reference pixels is referenced to generate an intra-prediction image.