Detection method of digital watermark about anti-attacking rotation based on Radon

This detection method is in use of defending rotation attack based on Radon transform characteristic.Performed Radon trans-form on original image and recorded outcome,then collected results on pending image in possible value with a certain step,finally a conclusion is obtained after comparing the two parts,the correlative number which is the biggest releases the rotation angle.Research shows that this method has good precision,it can be used as digital watermark detector for future.