Moving-picture encoding apparatus and moving-picture decoding apparatus

摘要

According to one embodiment, an encoding apparatus includes a prediction unit, a classifying unit, a first transformer, a second transformer, an order controller, and an entropy coder. The prediction unit obtains a predictive residual signal to be encoded, by using a mode selected from intra-prediction modes. The first transformer obtains first transformation coefficients by subjecting the signal to an orthogonal transformation by use of a first transformation basis if the selected mode is classified into a mode having a prediction direction. The first transformation basis is preset so that a coefficient density after the orthogonal transformation is higher than a coefficient density.

主权项

1. A moving-picture decoding apparatus, comprising:
an entropy decoder configured to obtain a prediction mode and transformation coefficients from coded data; an intra-prediction image generator configured to generate a prediction image signal according to the prediction mode; a classifying unit configured to classify the prediction mode into a first prediction mode preset in intra-prediction modes or a second prediction mode preset in the intra-prediction modes; an order controller configured to rearrange the transformation coefficients according to scanning order corresponding to the prediction mode from among scanning orders predetermined for intra-prediction modes; a first inverse orthogonal transformer configured to obtain a predictive residual signal by subjecting the rearranged transformation coefficients to an inverse orthogonal transformation by use of a first transformation basis if the prediction mode is classified into the first prediction mode; a second inverse orthogonal transformer configured to obtain a predictive residual signal in the second prediction mode by subjecting the rearranged transformation coefficients to the inverse orthogonal transformation by use of a second transformation basis different from the first transformation basis if the prediction mode is classified into the second prediction mode; and an adder configured to add the predictive residual signal and the prediction image signal, thereby generating a decoded image signal.