PROBLEM TO BE SOLVED: To allow a high efficiency coder to code an image into a digital signal with less code quantity and especially to code the image in the unit of blocks. SOLUTION: The prediction coder is provided with 1st coding means 8, 16 that code a block in upper/lower and left/right of part or all adaptive prediction blocks in a prediction block, and apply local decoding to the code to obtain a decoded image, with adaptive prediction subtractor means 5, 6, 10-15 that discriminate a prediction method based on a decoded image in upper/lower and left/right sides of the adaptive prediction block so as to obtain a vertical interpolation prediction signal in upper /lower sides with respect to each pixel in the adaptive prediction block or a horizontal interpolation prediction signal in left/right sides with respect to each pixel in the adaptive prediction block and to subtract the interpolation prediction signal from each pixel in the adaptive prediction block and with a 2nd coding means 8 that encodes the prediction residual signal to obtain a code.
展开▼
