Jiang Du Chaw-Seng Woo Binh Pham Recovery of Watermark Using Differential Affine Motion Estimation. 81-88 2005 conf/acsw/2005 ACSW Frontiers http://www.crpit.com/confpapers/CRPITV44Du.pdf db/conf/acsw/acsw2005.html#DuWP05