This paper reports a new anti-geometric attack watermarking algorithm based on the Contourlet transform.It presents the concept of space direction significant tree(SDST) using the Contourlet coefficients′ father and son relationship at different resolutions,and determines the important factors to embed watermark information.This paper calculates and compares the eigenvalues between the original image(the watermark has been embedded) and the receive image(under attack) to correct the image by the...