Patent ID: 8606026

Claim:
An image encoding device having: a displacement vector detection unit configured to search, given an encoding target block, for a signal with high correlation with an encoding target block using a locally-decoded image in a block in a same already encoded image signal so as to calculate, using a signal with the highest correlation as a displacement prediction signal, a displacement vector, which is a displacement in a screen between the encoding target block and the displacement prediction signal; an image analysis unit configured to measure or receive a frequency property of an input image in a unit of a screen as input information and to select, as a reduction filter coefficient used when generating a reduced image, a filter coefficient that allows a frequency property of the reduced image to be close to the frequency property of the input image; a reduced-image generation unit configured to generate a signal resulting from performing reduction at least either horizontally or vertically for the locally-decoded image in the block in the same already encoded image signal; and a reduced-image displacement vector detection unit configured to search, given the encoding target block, for a signal with high correlation with the encoding target block using the signal resulting from performing reduction thus generated by the reduced-image generation unit so as to obtain, using the signal with the highest correlation as the displacement prediction signal, the displacement vector, which is a displacement in the screen between a reduced encoding target block and the reduction displacement prediction signal; and a displacement prediction mode determination/signal generation unit configured to select a signal with high correlation with the encoding target block from the displacement prediction signal and the reduction displacement prediction signal and to output a displacement vector used for a signal selected as a prediction signal and information indicating a selection result, and wherein: the reduced image generation unit generates a reduced signal using the reduction filter coefficient selected by the image analysis unit; and a differential signal between the prediction signal and the encoding target block, the displacement vector, and the information indicating the selection result are encoded.