A procedure for the routinary correction of back-to-front degradations in archival manuscripts

Virtual restoration of the nowadays frequently available dig-ital copies of the human documental heritage is crucial for facilitating both the traditional work of philologists and paleographers and the automatic analysis of the contents. Here we propose a fast procedure for the correction of the typically complex background of recto-verso historical manuscripts, which does not need for a preliminary registration of the images of the two page sides. The simplicity of the procedure makes it suitable for the routinary use in the archives. The method consists of two stages, degradation identification and degradation cancellation. The first step performs the detection of both the primary text and the spurious strokes via soft segmentation based on the statistical decorrelation of the two recto and verso images. In the second step, the noisy pattern in the background is substituted with pixels that simulate the texture of the clean surrounding background, through an efficient technique of image inpainting. As shown in the experimental results, the proposed procedure is able to perform a fine and selective removal of the degradation, while preserving the original appearance of the manuscript.