共查询到19条相似文献,搜索用时 281 毫秒
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基于Turbo码的数字水印技术 总被引:1,自引:0,他引:1
利用水印系统与通信系统传输模型的相似性,在图像数字水印算法中引入Turbo码技术,在水印嵌入前经过Turbo码编码来提高系统的抗误码能力,水印的嵌入选择在DCT域图像中频进行,为了实现自适应嵌入水印,将原始图像分块并利用视觉掩蔽特性对图像块进行分类,根据分类的结果,将不同强度的水印分量嵌入到图像块的DCT低频系数中,实验结果表明,利用该算法实现的水印具有很好的视觉掩蔽效应和鲁棒性。 相似文献
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基于HVS感知模型与数据压缩的可逆图像水印算法 总被引:1,自引:1,他引:0
提出了一种基于人类视觉系统(HVS)感知模型和数据压缩技术可逆图像水印算法.算法首先将原始图像进行分块,每块进行DCT变换,利用JND模型对变换域系数进行处理,得到每个像素最大可提取的有效位并提取.将提取出的有效位串进行压缩,得到压缩位串,将水印信息与压缩位串连接在一起嵌入原始图像,同时记录边信息,包括每个像素点的最大可提取有效位数目以及嵌入位置,提取时可据此边信息完全恢复原始图像,并得到水印信息.容置的大小取决于所使用的压缩算法,使用游程编码进行压缩.同时,运用人类视觉系统的感知模型,保证了嵌入水印后的图像的视觉质量. 相似文献
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传统的基于分形编码的水印技术一般嵌入0,1序列,没有实现灰度图像嵌入。本文在研究正交化分形编码的基础上,利用正交化分形编码参数在迭代过程中的不变性,构造出水印嵌入变换函数,使水印直接嵌入解码参数。分数阶微分序列的引入有效解决了嵌入水印的保密性问题,使得在分形编码的过程中嵌入灰度水印的方法具有了可行性,实现了图像压缩与水印嵌入一体化技术。实验结果表明,水印嵌入对宿主图像的分形编码质量几乎没有影响,水印提取质量良好,且采用分数阶微分序列对灰度水印进行加密效果较好。 相似文献
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一种与JPEG图像压缩编码结合的细胞自动机域盲水印算法 总被引:2,自引:0,他引:2
该文结合JPEG图像压缩编码和细胞自动机,提出一种用于JPEG压缩图像的数字盲水印算法。该算法先用Moore型细胞自动机对水印图像进行置乱;随后用2维正交细胞自动机变换将原始灰度图像进行分解,并在分解后得到的低频细胞自动机域系数中嵌入置乱后的水印信息。最后将嵌入了水印的图像按JPEG图像压缩标准进行编码。水印的提取是在解码过程中进行的。实验结果表明,该水印算法有较好的隐藏性;对常见的攻击如JPEG压缩、滤波、剪切、旋转以及加性噪声攻击等有较好的鲁棒性。 相似文献
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基于正交扩频码和HVS的DCT域图像数字水印技术 总被引:2,自引:1,他引:1
胡鹏 《信息安全与通信保密》2008,(7):80-82
文章基于对数字水印通信模型与通信系统相似性的分析,提出了一种利用正交扩频码构造多个独立信道对同一水印进行重复正交嵌入的想法,并引入HVS模型,把图像分块在DCT域分成三类,然后采用不同的嵌入强度系数嵌入到DCT中频系数中,最后从多个独立信道分别提取水印并做合成。实验结果表明,该方案较一般的扩频水印方法对高斯噪声、JPEG压缩、剪切和中值滤波具有更好的鲁棒性。 相似文献
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提出了一种基于小波变换(DWT)和离散余弦变换(DCT)的图像扩频水印技术.该算法首先将原始图像进行DWT和DCT变换提取图像中重要的频率部分,将扩频后的水印图像嵌入到经变换后的原始图像中.然后利用扩频序列的自相关函数特征进行检测提取水印,将从受到攻击的图像中提取出的水印和原始水印的相似性进行计算得出实验结果,从而得出... 相似文献
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基于LDPC码的数字图像水印算法研究 总被引:1,自引:0,他引:1
传统的数字水印不具备抗比特攻击能力,本文提出一种基于LDPC码的数字水印算法,对水印图像编码,可抵御比特攻击。水印图像在进入高噪声信道前需要进行LDPC编码。本文给出了LDPC码的编码结构,可传播置信解码算法。通过仿真结果表明,该算法降低了水印图像在传输中的误码率,具有较强的鲁棒性。 相似文献
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提出一种基于矢量量化压缩编码(简称VQ编码)技术的水印策略,在对原图像进行VQ编码后,按码书中码字的相似程度对码字进行划分,根据待嵌入水印图像的大小产生一个随机序列作为密钥,然后根据密钥在压缩数据的特定位置嵌入水印。提出的水印策略,其主要特征在于水印既存在于原图像VQ编码后的压缩数据中,也存在于接收端VQ解码后的图像中。压缩后的数据在数据量上远小于原始数据,所以由它替代原图像携带水印,既节省存储空间,也减小了网络传输时间,特别适用于网络环境下的水印嵌入和提取。更重要的是,这种水印策略具有较好的鲁棒性,能够抵抗诸如裁剪、模糊、JPEG压缩等波形攻击和扭转几何攻击。 相似文献
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Po-Chyi Su Houng-Jyh Mike Wang C.-C. Jay Kuo 《The Journal of VLSI Signal Processing》2001,27(1-2):35-53
A scheme which integrates image compression and image watermarking in an effective way is proposed in this research. The image compression scheme under consideration is EBCOT (Embedded Block Coding with Optimized Truncation) which has been adopted in the verification model (VM) of the emerging JPEG-2000 image compression standard. The watermark is embedded during the process when the compressed bit-stream is formed, and can be detected on the fly in image decoding. Thus, watermark embedding and retrieval can be done very efficiently in comparison with other existing watermarking schemes. In addition to efficiency, the proposed scheme has many interesting features. The embedded watermark is robust against various signal processing attacks such as coding and filtering while the watermarked image maintains good perceptual quality. The watermark retrieval procedure does not require the knowledge of the original image. Furthermore, the watermark can be detected progressively and region of interest (ROI) watermarking can be accomplished easily. 相似文献
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Digital watermark technology is now drawing attention as a new method of protecting digital content from unauthorized copying. This paper presents a novel audio watermarking algorithm to protect against unauthorized copying of digital audio. The proposed watermarking scheme includes a psychoacoustic model of MPEG audio coding to ensure that the watermarking does not affect the quality of the original sound. After embedding the watermark, our scheme extracts copyright information without access to the original signal by using a whitening procedure for linear prediction filtering before correlation. Experimental results show that our watermarking scheme is robust against common signal processing attacks and it introduces no audible distortion after watermark insertion. 相似文献
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大容量多通道数字水印算法 总被引:1,自引:1,他引:0
现有许多数字水印算法基本上都是针对灰度图像的,彩色图像数字水印算法尚未得到充分研究,且所能嵌入水印的容量也不够大。本文提出的大容量多通道数字水印算法对这一问题进行了研究。该算法以彩色图像作为原始载体,通过数字水印压缩编码,载体图像颜色空间转换,彩色分量分块离散余弦变换,结合人眼视觉系统确定水印嵌入位置等措施,将二维水印图像嵌入到原始彩色载体图像中,且能嵌入较大容量的水印图像。实验结果表明,该算法不仅提高了水印容量,且对剪切、模糊、锐化等有损攻击具有良好的健壮性。 相似文献
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一种基于提升方案小波和小波块的图像水印算法 总被引:5,自引:2,他引:3
数字水印技术是多媒体信息安全领域的一个重要研究课题。文章提出一种基于提升方案小波和小波块的图象水印算法。首先,利用提升方案小波对宿主图像和水印图像进行分解,同时利用小波系数的树结构,将宿主图像的小波系数块按纹理密度分成两类,并根据嵌入位置所隶属的小波块的纹理强弱,嵌入不同强度的水印信息,这在一定程度上保证了所嵌入水印在不可见性前提下的极大鲁棒性。实验结果验证了所提出算法的有效性。 相似文献
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《Industrial Electronics, IEEE Transactions on》2001,48(5):875-882
In this paper, an image accreditation technique by embedding digital watermarks in images is proposed. The proposed method for the digital watermarking is based on the wavelet transform. This is unlike most previous work, which used a random number of a sequence of bits as a watermark and where the watermark can only be detected by comparing an experimental threshold value to determine whether a sequence of random signals is the watermark. The proposed approach embeds a watermark with visual recognizable patterns, such as binary, gray, or color image in images by modifying the frequency part of the images. In the proposed approach, an original image is decomposed into wavelet coefficients. Then, multi-energy watermarking scheme based on the qualified significant wavelet tree (QSWT) is used to achieve the robustness of the watermarking. Unlike other watermarking techniques that use a single casting energy, QSWT adopts adaptive casting energy in different resolutions. The performance of the proposed watermarking is robust to a variety of signal distortions, such as JPEG, image cropping, sharpening, median filtering, and incorporating attacks 相似文献
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VE. Jayanthi V. Rajamani P. Karthikayen 《International Journal of Electronics》2013,100(11):1565-1580
We present a technique for irreversible watermarking approach robust to affine transform attacks in camera, biomedical and satellite images stored in the form of monochrome bitmap images. The watermarking approach is based on image normalisation in which both watermark embedding and extraction are carried out with respect to an image normalised to meet a set of predefined moment criteria. The normalisation procedure is invariant to affine transform attacks. The result of watermarking scheme is suitable for public watermarking applications, where the original image is not available for watermark extraction. Here, direct-sequence code division multiple access approach is used to embed multibit text information in DCT and DWT transform domains. The proposed watermarking schemes are robust against various types of attacks such as Gaussian noise, shearing, scaling, rotation, flipping, affine transform, signal processing and JPEG compression. Performance analysis results are measured using image processing metrics. 相似文献