A method of periodic pattern localization on document images
Timofey S. Chernov, Dmitry Nikolaev, Vitali M. Kliatskine · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2015
Periodic patterns often present on document images as holograms, watermarks or guilloche elements which are mostly used for fraud protection. Localization of such patterns lets an embedded OCR system to vary its settings depending on pattern presence in particular image regions and improves the precision of pattern removal to preserve as much useful data as possible. Many document images’ noise detection and removal methods deal with unstructured noise or clutter on documents with simple background. In this paper we propose a method of periodic pattern localization on document images which uses discrete Fourier transform that works well on documents with complex background.