A watermark algorithm based on SVD and image geometric correction

An anti-geometric attack SVD digital watermark algorithm based on geometric center and image mass centroid is proposed. An improved block-based SVD is employed to embed and extract watermark. Based on the invariance of geometric center and image mass centroid, the conducted geometric transform can be detected, and the attacked image is corrected before extraction according to the detected transformation parameters. Experiments show that the proposed algorithm has low computational cost, good embedding capacity and shows perfect robustness in against large scale geometric deformation, the embedded watermark can be easily and exactly extracted.