A novel robust logo watermarking scheme using fractional M-band wavelet transform

Digital watermarking, means of hiding/inserting a message, which can be an image, audio, video or text within the digital media. This hidden/inserting message can be later being extracted or detected for a variety of purposes. In this paper, a novel multi-resolution logo watermarking scheme using fractional M-band wavelet transform (Fr-M-band-WT) is proposed. The watermark is embedded in the multiresolution Fr-M-band-WT coefficients of low frequency bands of the host image using singular value decomposition (SVD). A multi-resolution nature of Fr-M-band-WT is exploited in the process of edge detection. Experimental results of the proposed logo watermarking scheme are compared with the previously available watermarking algorithms, fractional Fourier transform (FrFT), fractional wavelet transform (FrWT). Further, the proposed watermark extraction scheme is also tested on different attacks. The results after being investigated the proposed watermarking scheme shows a significant improvement as compared to other existing methods.     

基于DCT变换的QWT域改进的图像盲水印算法

针对数字图像的版权保护,基于离散余弦变换和四元数小波变换,提出了一种新的改进的盲水印算法,先根据待嵌入水印的大小对载体图像进行四元数小波变换,获得与幅值和相位信息相对应的4幅低频子带,然后对每个低频子带分别进行全局离散余弦变换,最后通过修改两个随机子带中特定位置上DCT系数的大小关系嵌入水印,利用分阶线性Logistic映射产生的混沌序列预处理经Arnold置乱后的水印信息和确定水印的嵌入位置.实验结果表明,该算法对添加噪声、JPEG压缩、滤波和亮度及对比度调整等攻击都具有很强的鲁棒性.     

Wavelet tree quantization for copyright protection watermarking

This paper proposes a wavelet-tree-based blind watermarking scheme for copyright protection. The wavelet coefficients of the host image are grouped into so-called super trees. The watermark is embedded by quantizing super trees. The trees are so quantized that they exhibit a large enough statistical difference, which will later be used for watermark extraction. Each watermark bit is embedded in perceptually important frequency bands, which renders the mark more resistant to frequency based attacks. Also, the watermark is spread throughout large spatial regions. This yields more robustness against time domain geometric attacks. Examples of various attacks will be given to demonstrate the robustness of the proposed technique.     

一种基于ICA的图像水印方法

本文提出了一种结合离散小波变换(DWT)、离散余弦变换(DCT)和独立分量分析(ICA)的图像数字水印方法。该方法把原始图像进行二维小波分解，保留其高频细节信息，然后对小波逼近子图进行离散余弦变换并嵌入水印。水印的检测使用了ICA方法。实验结果表明该水印方案很好的实现了水印的鲁棒性与不可见性的统一，对各种攻击具有很好的鲁棒性。同时由于ICA方法的引入，较好的改善了水印的检测效果。     

一种基于图像内容的小波域半脆弱水印算法

在充分考虑图像视觉屏蔽特性的基础上,提出一种小波域图像半脆弱水印算法.嵌入水印基于小波低频子带系数产生,该方案通过自适应地修改小波变换后水平与垂直细节子带系数以嵌入水印,嵌入水印具有较好的透明性.实验结果证明了算法对非恶意攻击的鲁棒性和对恶意攻击的脆弱性.     

一种有效抵抗裁剪攻击的小波域盲水印算法

该文提出了一种有效抵抗裁剪攻击的小波域盲水印算法,能从小的图像块上检测出水印。首先将图像进行小波变换,选择两个所需要的子带,利用相邻特征平均值和奇偶判决法在两个子带上各自重复内嵌一半水印,在水印检测过程中不需要原始图像。实验结果表明,该算法具有较好的透明性,对各种攻击有较强的鲁棒性,尤其是明显增强了小波域水印在面临裁剪攻击和联合攻击时的鲁棒性。     

A robust color image watermarking algorithm against rotation attacks

A robust digital watermarking algorithm is proposed based on quaternion wavelet transform (QWT) and discrete cosine transform (DCT) for copyright protection of color images. The luminance component Y of a host color image in YIQ space is decomposed by QWT, and then the coefficients of four low-frequency subbands are transformed by DCT. An original binary watermark scrambled by Arnold map and iterated sine chaotic system is embedded into the mid-frequency DCT coefficients of the subbands. In order to improve the performance of the proposed algorithm against rotation attacks, a rotation detection scheme is implemented before watermark extracting. The experimental results demonstrate that the proposed watermarking scheme shows strong robustness not only against common image processing attacks but also against arbitrary rotation attacks.     

一种新的基于复合变换域灰度数字水印算法

文章提出了一种新的结合Arnold置乱变换的复合变换域灰度数字水印嵌入算法。该算法利用系数间的相关性对原始图像离散小波变换后的低频系数LL进行离散余弦变换,然后在其中嵌入水印,在嵌入水印之前对Arnold变换预处理的灰度水印图像作离散余弦变换,这样增强了水印的鲁棒性和不可见性。实验结果证明,该算法能有效抵抗JPEG图像压缩和常见的图像处理操作攻击。     

基于DWT-QDFT的硬拷贝彩色图像全息水印

提出了一种基于离散小波变换(DWT)及四元数傅里 叶变换(QDFT)的鲁棒性全息水印算法。首先对RGB彩色图像的三个色彩分量分 别做DWT,取变换后的3个低频部分组成纯四元数矩阵;随后对其进行QDFT ,将全息水印通过替代QDFT的实部的中频系数进行嵌入,再经过逆QDFT及小波重构得到含有 水印的彩 色图像。攻击测试结果表明,本文算法对于常规的信号处理有很好的鲁棒性;打印扫描实验 证明,本文算法具有抵 抗硬拷贝攻击的能力。四元数傅立叶变换的引入,实现了小波低频系数的嵌入保证了算法的 鲁棒性,同时 又结合了四元数在处理彩色图像中的优势,双变换域的采用与全息方法的结合实现了算法应 用于硬拷贝彩 色图像中鲁棒性及不可见性之间的平衡。本文全息水印方案可以应用于印品水印防伪领域。     

Quantisation-based video watermarking in the wavelet domain with spatial and temporal redundancy

In this article we introduce a new public digital watermarking technique for video copyright protection working in the discrete wavelet transform domain. The scheme uses binary images as watermarks. These are embedded in the detail wavelet coefficients of the middle wavelet sub-bands. The method is a combination of spread spectrum and quantisation-based watermarking. Every bit of the watermark is spread over a number of wavelet coefficients with the use of a secret key. The resilience of the watermarking algorithm was tested against a series of eight different attacks using different videos. To improve the resilience of the algorithm we use error correction codes and embed the watermark with spatial and temporal redundancy. The proposed method achieves a very good perceptual quality with mean peak signal-to-noise ratio values of the watermarked videos of more than 40 dB and high resistance to a large spectrum of attacks.     

基于DWT域图像数字水印技术

提出了一种基于DWT域的自适应盲检测数字水印算法,将二值水印图像自适应地嵌入到经小波变换后的原始图像的逼近子图上。实验结果显示,不论是视觉主观还是客观计算上,此算法得到的水印图像都具有很好的不可见性,对常见图像攻击和处理后的水印检测情况证明此算法所得的水印图像具有很强的鲁棒性。     

一种基于DWT-DCT变换域的全息水印技术

在研究傅里叶全息技术基础上,提出了一种结合离 散小波变换和离散波变换(DWT-DCT)变换的彩色图像数字水印算法,使得水印 拥有强鲁棒性和不可见性。首先,对水印信息进行傅里叶变换,并生成全息水印图; 其次,将载体图 像在RGB空间内的蓝色B分量进行小波分解,对其低频部分进行DCT;最后, 将水印全息图嵌入其高频系数 中。实验结果发现,以k=0.05的强度嵌入水印后,含水印图像的峰值 信噪比(PSNR)达到47,能有效抵抗 信号处理和裁切攻击,同时提取出的水印和原始水印的相似性(NC值)能保持在0. 75以上,说明本文水印 算法有较强的鲁棒性和不可见性。本文算法能够抵抗裁切、滤波、噪声和JPEG压缩攻击,可 用于数字图像版权保护方面。     

离散小波变换和奇异值分解相融合的彩色图像水印算法

为加强数字多媒体的版权保护,提出了一种结合离散小波变换和奇异值分解相融合的彩色图像水印算法(DWT-SVD).首先对彩色数字载体图像进行小波分解,并对其小波系数进行奇异值分解;然后对水印信息采用Arnold进行置乱,并进行奇异值分解;最后将水印信息的奇异值嵌入到彩色图像的小波系数奇异值中,并对水印嵌入强度进行调节.仿真结果表明,DWT-SVD可以检测到完整的水印信息,具有良好的不可见性,对各种攻击具有较强的鲁棒性.     

Robust watermarking against print and scan attack through efficient modeling algorithm

This article proposes a blind discrete wavelet transform-discrete cosine transform (DWT-DCT) composite watermarking scheme that is robust against print and scan distortions. First, two-dimensional DWT is applied to the original image to obtain the mid-frequency subbands. Then, a one-dimensional DCT is applied to the selected mid-frequency subbands to extract the final coefficients for embedding the watermark. To specify watermarking parameters, we utilize a Genetic Algorithm to achieve a predefined image quality after watermark insertion. Suitable locations for watermarking are determined by analyzing the effect of a modeling algorithm. This model simulates noise and nonlinear attacks in printers and scanners through noise estimation and system identification methods. The experimental results demonstrate that the proposed algorithm has a high robustness against print and scan attack such that its robustness is higher than related watermarking algorithms.     

基于QR分解的强鲁棒性双彩色盲水印算法

提出了一种将彩色快速识别(QR)码作为水印嵌入彩色宿主图像的强鲁棒性盲水印算法。首先 对彩色宿主图像分通道进行离散小波 变换(DWT)和分块QR分解得到非重叠的酉矩阵,然后将QR码分通道置乱加密归一化后嵌入到 宿主图像对应通道 酉矩阵的系数差中。仿真实验结果表明,本算法在满足不可见性的同时具有较强的鲁棒性; 相比现有算法, 本算法不仅能够抵抗旋转和裁切攻击,在JPEG压缩和噪声滤波攻击方面的抵抗能力也有较 大提升;而且本算法属于盲水印技术,具有较大的实际应用价值。     

基于NSCT和DFRFT的数字水印算法研究

为了有效地克服外界攻击对数字水印的破坏性,增强数字水印的鲁棒性,提出了一种基于非下采样轮廓波变换(Nonsample Contourlet Transform,NSCT)与离散分数阶傅里叶变换(Discrete Fractional Fourier Transform,DFRFT)相结合的数字水印算法.首先,通过Logistic置乱处理水印信号,增强水印的安全性;然后,对宿主图像进行NSCT分解,对其中的低频分量进行DFRFT分解;最后,将置乱的水印图像嵌入到DFRFT分解系数中,从而进一步加强水印的不可见性和鲁棒性.实验结果表明,该算法不仅具有较好的鲁棒性,还可以有效地抵抗外界攻击.     

Hiding digital watermarks using multiresolution wavelet transform

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     

基于DWT-SVD的大容量音频水印算法

在音频水印领域,嵌入大量水印而不影响宿主音 频的听觉质量,同时具有良好的鲁棒 性,仍然是一项具有挑战的工作。针对这一问题,本文提出了一种大容量,透明,鲁棒的音 频水印算法。首先对音频应用2级离散小波变换(DWT),并选取低频分量作奇异值分解(SV D),然后将水印嵌入在奇异值矩阵的非对角线元素中,可同时提高算法的透明性和嵌入容 量。另外,利用汉明码编码提升水印的鲁棒性和安全性。仿真实验结果表明,所提算法在平 均信噪比37.75 dB的情况下,可以达到5512 bps 的嵌入容量,对噪声添加、滤波、剪切、压缩等各种信号处理攻击具有良好的鲁棒性。     

A blind scene-based watermarking for video copyright protection

Due to the replicable nature of video many illegal copies of the original video can be made. So it demands to deliver methods for preventing illegal copying. This paper identifies a new digital watermarking approach for copyright protection of video based on wavelet transformation. First, the motion part of color video is detected by scene change analysis, and then by applying 3D wavelet transformation over detected motion part, 10 sub-bands of wavelet coefficients are obtained. In order to insert the watermark, 3D coefficients of HL, LH and HH with their third level are selected. After all, by using a spread spectrum technique, the watermark is embedded into the selected wavelet coefficients. In extraction step, the original video is not needed, namely, blind detection. So, the resultant watermarking scheme can be used for public watermarking applications, where the original video is not available for watermark extraction. The experimental results show a good performance of the proposed method for transparency and robustness. Furthermore, the robustness of the proposed method against various kinds of attacks such as median filtering, Gaussian noise, frame dropping, frame averaging, frame swapping and lots of lossy compression including MPEG-4, MPEG-2, and H.264 shows the fidelity of our claim.     

Robust image watermarking based on multiband wavelets and empirical mode decomposition.

In this paper, we propose a blind image watermarking algorithm based on the multiband wavelet transformation and the empirical mode decomposition. Unlike the watermark algorithms based on the traditional two-band wavelet transform, where the watermark bits are embedded directly on the wavelet coefficients, in the proposed scheme, we embed the watermark bits in the mean trend of some middle-frequency subimages in the wavelet domain. We further select appropriate dilation factor and filters in the multiband wavelet transform to achieve better performance in terms of perceptually invisibility and the robustness of the watermark. The experimental results show that the proposed blind watermarking scheme is robust against JPEG compression, Gaussian noise, salt and pepper noise, median filtering, and ConvFilter attacks. The comparison analysis demonstrate that our scheme has better performance than the watermarking schemes reported recently.