1. A method for analyzing an image of a printed object to determine whether the printed image is a copy or an original, the method comprising: determining whether a machine readable auxiliary signal is embedded in the image, wherein the auxiliary signal is embedded at embedding locations using a set of two or more print structures that change in response to a copy operation, the change causing a divergence or convergence of a characteristic of the print structures such that the machine readable signal becomes more or less detectable; and based on evaluating the machine readable auxiliary signal, determining whether the printed object is a copy or an original.