An image processing device is composed of an image drawing section, an image input section, a corresponding-point searching section, and a processing parameter improving section. The image drawing section has a preset three-dimensional model image to draw a three-dimensional image on the basis of the three-dimensional model image and a first processing parameter. An input image of a still image or a motion picture is input to the image input section. The corresponding-point searching section searches for that point on the input image input to the image input section which corresponds to a certain point on the three-dimensional image drawn by the image drawing section, to obtain corresponding-point position information. The processing parameter improving section uses the corresponding-point position information obtained by the corresponding-point searching section to improve a value for the first processing parameter to determine a second processing parameter.