Description: Matlab source code for DCT-based watermarking for grayscale images. DCT-based watermark recovering without resorting to the uncorrupted original image. Digital watermarking has been proposed as a viable solution to the need of copyright protection and authentication of multimedia data in a networked environment, since it makes possible to identify the author, owner, distributor or authorized consumer of a document.
A new watermarking technique to add a code to digital images is presented: the method operates in the frequency domain embedding a pseudo-random sequence of real numbers in a selected set of DCT coefficients. Watermark casting is performed by exploiting the masking characteristics of the Human Visual System, to ensure watermark invisibility. The embedded sequence is extracted without resorting to the original image, so that the proposed technique represents a major improvement to methods relying on the comparison between the watermarked and original images.
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Size: 98304 |
Author:omar |
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Description: 本文算法是将24 位真彩图的亮度分量分块
DCT ,然后利用DCT 量化系数的奇偶特性嵌入8
位灰度水印图,并通过PN 序列加密来保证水印的
安全性。算法中,将灰度图像转换为二进制数据
流,置乱后扩频调制,隐藏在宿主DCT 系数量化值
中,提取时不需要宿主信号,实现水印信号的盲提
取。-This algorithm is 24-bit true color pictures of the luminance component of block DCT, quantization DCT coefficients and then use the parity properties of 8-bit grayscale watermark embedding map, and through the PN sequence of encryption to ensure the security of the watermark. Algorithm, the gray image into binary data stream, scrambling after the spread spectrum modulation, hidden in the host DCT coefficient quantization values, the extraction does not require the host signal, the blind watermark extraction. Platform: |
Size: 284672 |
Author:王秀梅 |
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Description: 作为信息隐藏的重要分支，数字水印是一种有效的数字产品版权保护和数据安全维护技术。近年来数字水印技术成为了信息安全领域的研究热点，也得到了较大的发展。基于变换域的水印技术是目前研究的热点和重点。本文系统介绍了数字水印的原理和应用方法，概要介绍了数字水印的几种主流算法，并重点研究了一种基于离散余弦变换(DCT)数字图像水印算法，并借助 MATLAB编程工具，实现数字水印的嵌入和提取仿真，以及为测试鲁棒性而对水印图像进行攻击实验。-As an important branch of information hiding, digital watermarking is an effective copyright protection of digital products and data security maintenance technology. In recent years, digital watermarking has become a hot research field of information security, has also been considerable development. Transform domain watermarking technique based on the current research focus and focus. This system describes the principles and applications of digital watermarking methods, an overview of several mainstream digital watermarking algorithms, and focus on a discrete cosine transform (DCT) digital image watermarking, and with the MATLAB programming tools, digital watermark embedding and extraction simulation, as well as test the robustness of the watermark image on the attack experiments. Platform: |
Size: 2048 |
Author:yang cheng |
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Search - watermark data in DCt matlab