1. A qualifier tool, comprising: an optical imaging system configured to generate an inspection image corresponding to a photo-mask; at least one processor; at least one memory; and at least one program module, the program module stored in the memory and configured to be executed by the processor to inspect a photo-mask, the program module including instructions for iteratively reconstructing a first estimated pattern corresponding to the photo-mask at an object plane of the optical imaging system, wherein the first estimated pattern has a higher resolution than a second estimated pattern at the object plane; and wherein the second estimated pattern is determined from the inspection image by correcting for a transfer function of the optical imaging system.