| 摘要 |
<p>An encoded bit stream is processed by a reversible decoder unit (52), a dequantization unit (53) and an inverse orthogonal transform unit (54) in the named order, thereby obtaining the encoding parameter information and coefficient data as orthogonally transformed. The inverse orthogonal transform unit (54) uses a preset base to perform an inverse orthogonal transform of the coefficient data in accordance with the position of a transformed block in a macro-block indicated by the encoding parameter information, thereby obtaining prediction error data. An intra-prediction unit (62) generates predicted image data. An addition unit (55) adds the predicted image data to the prediction error data, thereby decoding the image data. Thus, the use of the base that has been set in accordance with the position of a transformed block allows an optimum inverse orthogonal transform to be performed, whereby the encoding efficiency can be improved.</p> |
