Meaningful binary gray scale images was used as watermarking. Through Arnold transform, the watermarking image was hashed to eliminate the spatial correlation among pixels. Consequently, the algorithm’s ability to withstand attacks (for example cutting) was enhanced. The security of watermarking was enhanced by improving Arnold transform. With a quantification method, the original image is not required for extracting the watermarking. Numerical experiments show that the proposed algorithm is strong in withstanding cutting attacks. Even if more than one half of the image is cut off, the extracted watermarking still has good visual effects. After JPEG compression, adding noises, filtering, sharpening, blurring, contamination, distortion and other image processing or attacks, we can still extract relatively clear watermarking images.
