Self-Recognized Image Protection Technique that Resists Large-Scale Cropping

Brought up by the crucial issue of copyright, digital watermarking plays a key role in protecting integrity and providing authorization for multimedia. Efficient watermarking techniques require visual imperceptibility and robustness against various attacks. In this new approach, the authors propose a feature-based watermarking algorithm to embed a binary image as a watermark in the DCT domain to guarantee visual efficiency. In particular, the technique embeds marker bits to locate the original block of a cropped image and thereby resist synchronous damage to images. As simulation results show, compared to related methods, the proposed approach better resists several major image attacks, including cropping, shifting, blurring, noise, sharpening, and JPEG lossy compression. Moreover, this watermarking method can achieve blind extraction, in which the original image isn´t required for watermark extraction and the embedded image can be restored with high visual efficiency.