the invention concerns an image - processing apparatus , in which a high - frequency component signal of an original image - signal , representing a plurality of pixels , is added to either the original image - signal or a lowest frequency image - signal of the original image - signal , in order to generate a processed image - signal . the image - processing apparatus includes : a conversion - processing section to apply a conversion - processing to unsharp image - signals , generated from the original image - signal in respect to a plurality of frequency bands , so as to generate converted unsharp image - signals ; a differential processing section to generate differential image - signals obtained from differences between the unsharp image - signals and the converted unsharp image - signals ; and an addition - processing section to totally add the differential image - signals to generate the high - frequency component signal of the original image - signal .