基于DCT变换的数字水印技术的研究与仿真

Research and Simulation of Digital Watermarking Technology Based on DCT Transform

随着数字时代的飞速发展,以数字水印作为各类数字产品版权保护的支撑技术得到了迅猛的发展。文章针对基于DCT变换的数字图像水印算法进行研究。首先对水印图像进行预处理,提取图片、产生不同随机序列,提高一定的安全性;其次,采用分块进行DCT变换,选择中频系数嵌入水印信息;最后,通过DCT逆变换将水印提取出来,观察水印的完整性和图片是否被破坏。通过高斯噪声、剪切、旋转的方式对图像进行攻击,测试图像的鲁棒性。通过与LSB算法进行仿真对比,结果表明,本文算法不仅具有较好的透明性,而且也具有一定的鲁棒性。

With rapid development of the digital era,digital watermarking has developed rapidly as a supporting technology for copyright protection of various digital products.This paper studies the digital image watermarking algorithm based on DCT domain.Firstly,the watermark images are preprocessed to extract images,and generate different random sequences to improve the security.Secondly,the DCT domain transform is performed by block,and the IF coefficients are selected to embed the watermark information.Finally,the watermark is extracted by DCT inverse transform to observe the integrity of the watermark and whether the image is corrupted or not.Gaussian noise,cutting and rotation were used to attack the image to test the robustness of the image.By comparing with LSB algorithm,the results show that the proposed algorithm not only has better transparency,but also has better robustness.