An improved method for digital image fragile watermarking based on chaotic maps

In this paper, the digital image fragile watermarking method based on chaotic maps is proposed. Our method has some significant advantageous in comparison with other available methods. Firstly, we reduce watermark payloads, while they have high quality of recovery and security. In watermark embedding phase, we process the image in order to produce the information array for each block, which finally embedded in the host image to build watermarked image. The information array for each block has different length, which is defined based on block characteristic that could be smooth or rough. The second superiority of the proposed method is proposing a new metric for calculating roughness of image block, which leads to less consume of bandwidth in comparison with other available methods. Finally, we use chaotic map for block-mapping that enhances the security. Our method provides basic requirements of watermarking scheme such as, invisibility, recover quality and security. Experimental Results have proved that our method is powerful in tamper detection, self-recovery and robust against known watermarking attacks.