Print defect detection

Systems, methods, and software to automatically detect print defects in printed matter. Some embodiments include receiving a reference image and a scanned image, wherein the reference image and the scanned image are of the same subject matter and generating a plurality of detail maps of the reference image and the scanned image at each one or more resolutions to derive one or more detail maps of each image at each resolution. The detail maps, in some embodiments, are generated by identifying differences between pixels in each of one or more directions. The embodiments further include dividing the detail maps of each image into blocks of equal image proportion and calculate an activity measure of each block in each of the detail maps. These embodiments further calculate similarity measures between the blocks of reference image detail maps and the respective blocks of the scanned image detail maps.