A semi-automatic deshredding method based on curve matching

We present a semi-automatic method to reconstruct shredded documents. The novelty of the method lies in the way it performs pairwise matching of chads. The technique divides chad contours into curves using corner detection and introduces a procedure to assess the match of two curves. The proposed curve matching technique is robust to translation and rotation and can cope with shape deformations due to shredding by allowing overlapping of chads during matching. The alignment of text lines, crossing characters and color information on the chads is also utilized to improve matching performance. Visual interfaces are designed to allow for user input in identifying correctly matching chad pairs and reconstructing the document. The effectiveness of the method is demonstrated by solving the first and second puzzles of the DARPA shredder challenge.