1. An image processing device comprising: an image drawing section which 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 image input section to which an input image of a still image or a motion picture is input; a corresponding-point searching section which 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; and a processing parameter improving section which 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.