| 摘要 |
<p>PURPOSE:To raise the detecting capacity of a transmitting mode and to improve the picture quality of a reproducing picture by setting a threshold value corresponding to a transmitting mode change to the picture element data of respective picture element blocks received by a mode memory means and a threshold value setting means. CONSTITUTION:A block distortion operating means 90, which operates a block distortion to a previous picture on respective picture element blocks, a mode memory means 91, which stores the transmitting mode of the respective picture element blocks of the previous picture, a threshold value setting means 92, which refers to the block distortion, channel quality and the transmitting mode of the previous picture stored in the mode memory means 91 and sets a threshold value to respective transmitting mode changes between the previous picture and a present picture, and an evaluating means 84, which evaluates the transmitting mode of the respective picture element blocks of the present picture according to the threshold value, are provided. Thus, the transmitting mode change, of which picture quality improving effect is the highest, is selected maximumly, the change which has possibility to make the picture quality worse can be made not to be selected much, and the improvement of the picture quality and a data compressing ratio by a third mode to use the data of the previous picture can be exhibited maximumly.</p> |
