1. An image evaluating apparatus comprising: a relative position calculator for calculating two-dimensional relative positions between an image formation position of one color plate of a plurality of color plates and image formation positions of other color plates, based on known positional information of registration marks formed by the color plates and positional information of the registration marks that are actually formed as images on a recording medium; and a position expressing image generator for generating a position expressing image which represents the relative positions calculated by the relative position calculator, by way of two-dimensional positional coordinates.