| 摘要 |
A moving-picture encoding apparatus, includes a prediction unit configured to obtain a predictive residual signal to be encoded, by using an intra-prediction that corresponds to a mode selected from a plurality of intra-prediction modes, a classifying unit configured to classify the selected mode into a first prediction mode indicating an intra-prediction using a prediction direction or a second prediction mode indicating an intra-prediction using no prediction direction, a first orthogonal transformer configured to obtain a plurality of first transformation coefficients by subjecting the predictive residual signal to an orthogonal transformation by use of a first transformation basis if the selected mode is classified into the first prediction mode, the first transformation basis being preset so that a first coefficient density after the orthogonal transformation is higher than a second coefficient density before the orthogonal transformation, a second orthogonal transformer configured to obtain a plurality of second transformation coefficients by subjecting the predictive residual signal to the orthogonal transformation if the selected mode is classified into the second prediction mode, an order controller configured to rearrange the obtained one of the first transformation coefficients and the second transformation coefficients according to scanning order corresponding to the selected mode from among scanning orders predetermined for the intra-prediction modes, and an entropy coder configured to encode the rearranged transformation coefficients and information indicating the selected mode. |
