A first intermediate image generating means (1) generates an intermediate image (D1) by extracting a component of an input image DIN in a particular frequency band; a second intermediate image generating means (2) generates an intermediate image D2 having a frequency component higher than the intermediate image (D1); a first intermediate image processing means (3M) generates an intermediate image (D3M) by amplifying the pixel values in the intermediate image (D1); a second intermediate image processing means (3H) generates an intermediate image (D3H) by amplifying the pixel values in the intermediate image (D2); and an adding means (4) adds the input image (DIN) and the intermediate image (D3M) and the intermediate image (D3H) together to obtain an output image (DOUT). A first amplification factor (D3MA) and a second amplification factor (D3HA) are determined according to pixel values in the input image (DIN). Even if the input image includes a fold-over component on the high-frequency side or does not include an adequate high-frequency component, an enhanced image can be provided without causing overshoot.
