一种用于版权认证的数字图像水印算法

提出了一种基于DWT域的用于图像版权认证和保护的数字图像水印方法。首先,将原始图像分块,并对每块进行多层DWT变换;然后,把置乱的水印图像嵌入到图像的多层低频小波系数上;最后,再对图像进行IDWT变换。文中所采用的二值标识水印图像直观,信息量大,并根据实际需要,用航拍图像作为载体图像进行实验。实验结果表明,该方法简单高效, 可嵌入的数字水印信息容量大,对一般的图像处理和各种攻击有很好的鲁棒性,如:JPEG压缩、滤波、加噪声、旋转、缩放,涂抹、剪切等,能够准确可靠地提取水印。

A Digital Image Watermarking Algorithm for Copyright

The paper gives a digital image watermarking algorithm based on DWT domain for image copyright and protection. Firstly, the original image is divided into small blocks and each block is DWT transformed. Secondly, the scrambled watermarking image is added into the low-frequency wavelet coefficients of multiresolution representation of the original image. Finally, each block is IDWT transformed. This paper adopts binary identified watermark which is intuitionist and has a large amount of information. And on the basis of the factual need, we adopt the airscape as a host image to do experiment. Experimental results show that the method is not only simple, effective, with nigh capacity of watermark, but also is robust against normal image processing and kinds of attacks, such as JPEG compression, filtering, adding noise, rotating, zooming, daubing and cropping. And it can detect the watermark credibly.