This paper proposes a novel method for document enhancement. The method is based on the combination of two state-of-the-art filters through the construction of a mask. The mask is applied to a TV (Total Variation) -regularized image where background noise has been reduced. The masked image is then filtered by NLmeans (Non-Local Means) which reduces the noise in the text areas located by the mask. The document images to be enhanced are real historical documents from several periods which include several defects in their background. These defects result from scanning, paper aging and bleed-through. We observe the improvement of this enhancement method through OCR accuracy.
Barney Smith, Elisa H.; Darbon, Jerôme; and Likforman-Sulem, Laurence. (2011). "A Mask-Based Enhancement Method for Historical Documents". Proceedings of SPIE-IS&T Electronic Imaging, 7874. http://dx.doi.org/10.1117/12.876668