Recto-verso registration, enhancement and segmentation of ancient documents

This paper presents some experiments on different image processing techniques combined and adapted to define a procedure aimed at improving the readability of ancient degraded documents. The focus is on documents affected by the bleed-through effect, which significantly reduces readability. The availability of the recto and verso scans of any single page is assumed. The proposed procedure is composed of three steps: recto-verso registration, image enhancement through statistical decorrelation and, finally, image segmentation. As the registration step can strongly influence the results obtained during the subsequent phases, we carried out a comparison of different registration algorithms, in order to evaluate their overall effectiveness on recto-verso processing.