数字水印, 二值图像, 图像认证, 混沌加密

A novel digital watermarking technique was proposed for authenticating binary images.The pixels in binary image were divided into two categories,one was the flippable pixels and another was the unflippable pixels. In the watermark generation process, the unflippable pixels were input into a Hash function for generating the authenticating signals which depended on the content of the image, and then the authenticating signals and the image ownership information were encoded with a chaotic sequence to form the watermark. The watermarked image can be obtained by inserting the watermark into the flippable pixels. Experimental results show that the watermark can be blindly extracted, the proposed method can detect any modification to the watermarked image, and verify the ownership while the watermarked image is not manipulated.