Trinary Image Mosaicing Based Watermark String Detection

Watermark string detection is very useful for document security protection. In [2], we proposed an image based document watermark detection system. In this paper, two major modifications are made based on the previous system.First, a trinary image mosaicing algorithm is proposed to merge the broken watermark string images into a high quality mosaic image. Second, we relax the conditions in the Maximum Clique based keyword detection algorithm.The new algorithm can handle watermark string with variant spacing. Therefore, not only English keywords, but also Japanese/Chinese keywords can be processed. The Experimental results show the effectiveness of our algorithm.