一种基于小波系数块的鲁棒数字水印

摘要

提出了一种基于小波系数块的数字水印算法,首先对载体图像进行小波分解,将低频子图分割成互不重叠的系数块,然后将置乱后的水印嵌入到系数块的平均值上,经过一系列信号处理,系数块的平均值不会有很大改变,并使用模运算,以增强水印的鲁棒性.实验表明该算法对诸如旋转、缩放等几何变换和常规的图像处理具有较强鲁棒性.%Digital watermark is an effective method in data authentication and protection of the copyright, to enhance its robustness. This paper puts forward a digital image watermarking algorithm based on the wavelet coefficients block. In the embedding, the lowest frequency components of the source image which were transformed into discrete wavelet transform ( DWT) were divided non-overlap blocks, then embedded the watermark which was scrambled in the average value of the blocks, after a series of signals handling, the average of coefficient block does not have a great change, and using of modular arithmetic enhances the robustness of watermark. The experimental results show that the processing of the proposed algorithm is robust against geometric attacks such as rotating attack, scaling attacks, as well as common signals processing.