MOVING IMAGE ENCODER AND MOVING IMAGE DECODER

摘要

PROBLEM TO BE SOLVED: To provide orthogonal transformation base selection encoding technology with a small circuit scale.SOLUTION: A moving image decoder includes: an acquisition section for acquiring a transformation coefficient from encoded data; a coefficient order control section for rearranging the transformation coefficient in accordance with a scan order corresponding to a prediction direction of a target block; a classification section for classifying a processing mode applied to the target block into a first mode or a second mode; a first inverse orthogonal transformation section for inversely orthogonally transforming the rearranged transformation coefficient and acquiring a predicted error signal by using a common first transformation base without depending on the plurality of prediction directions when the processing mode is classified into the first mode; a second inverse orthogonal transformation section for inversely orthogonally transforming the rearranged transformation coefficient and acquiring the predicted error signal by using one second transformation base different from the first transformation base when the processing mode is classified into the second mode; and a decoded image signal generating section for generating a decoded image signal by using the predicted error signal. The coefficient order control section rearranges the transformation coefficient in accordance with the scan order in a horizontal direction when the prediction direction of the target block is a vertical direction.