The invention corrects for rotational misalignment of images having a prominent periodic structure in a preferred direction, particularly imaged text pages. It preferably also finds the degree of correlation between different images. First the rotational misalignment of an imaged page is detected and...http://www.google.es/patents/US6285802?utm_source=gb-gplus-sharePatente US6285802 - Rotational correction and duplicate image identification by fourier transform correlation
Rotational correction and duplicate image identification by fourier ...
