An improved color image watermarking scheme based on Schur decomposition

Multimedia Tools and Applications - With the rapid development of computer technology, the copyright protection of color image is becoming a more and more urgent problem. In this paper, an improved...     

Weighted matrix based reversible watermarking scheme using color image

High capacity, secure, reversible watermarking scheme using a color image for image authentication and tampered detection is still an important area of research. In this investigation, we have proposed a weighted matrix based reversible watermarking scheme using the color image which provides image authentication and tampered detection. Here, we decomposed the original image into R, G, B color components and partitioned into (3 × 3) pixel blocks then we performed the sum of entry-wise-multiplication operations using a modified weighted matrix to embed the watermark. The watermark embedding locations are stored within an index file to enhance security, increase data hiding capacity, gain good visual quality, achieve reversibility and confirm authenticity. The proposed watermarking scheme not only perform authentication and tampered detection but also improved both data embedding capacity up to 8.00 (bpp) as well as increase visual quality measured by PSNR, 50.03 (dB). Finally, the scheme is compared with other existing state-of-the-art methods and gives a reasonably better performance in terms of visual quality and hiding capacity. Our scheme has been evaluated through various steganographic analysis and observed that the scheme is secure and robust against various attacks.     

A majority-voting based watermarking scheme for color image tamper detection and recovery

This paper presents a novel color image watermarking scheme for both tamper detection and tampered image recovery. The proposed scheme embeds watermarks consisting of the authentication data and the recovery data into image blocks. In the tamper detection process, instead of independently examining each embedded authentication data, we take all the authentication data embedded in an image into account and utilize a majority-voting technique to determine the legitimacy of image blocks. Experimental results show that the proposed scheme can effectively thwart collage attack and vector quantization (VQ) attack, while sustaining superior accuracy of tamper localization. Furthermore, the results reveal that the tampered images can be successfully recovered with acceptable visual quality.     

A novel color image watermarking scheme in nonsampled contourlet-domain

Geometric distortion is known as one of the most difficult attacks to resist, for it can desynchronize the location of the watermark and hence causes incorrect watermark detection. It is a challenging work to design a robust color image watermarking scheme against geometric distortions. Based on the support vector regression (SVR) and nonsubsampled contourlet transform (NSCT), we propose a new color image watermarking algorithm with good visual quality and reasonable resistance toward geometric distortions in this paper. Firstly, the geometrically invariant space is constructed by using color image normalization, and a significant region is obtained from the normalized color image by utilizing the invariant centroid theory. Then, the NSCT is performed on the green channel of the significant region. Finally, the digital watermark is embedded into host color image by modifying the low frequency NSCT coefficients, in which the HVS masking is used to control the watermark embedding strength. In watermark detection, according to the high correlation among different channels of the color image, the digital watermark can be recovered by using SVR technique. Experimental results show that the proposed color image watermarking is not only invisible and robust against common image processing operations such as filtering, noise adding, and JPEG compression etc., but also robust against the geometrical distortions.     

基于HVS的多通道DCT彩色图像水印算法

提出了一种基于离散余弦变换(DCT)的彩色盲水印算法,首先将彩色图像由RGB彩色空间转换到YCbCr彩色空间,利用其良好的空间独立性,分别对三个空间进行DCT,并根据人眼视觉特性自适应选择嵌入量,嵌入水印.实验结果表明,嵌入算法容易实现,且该水印算法具有很好的不可见性,并对剪切和JPEG压缩等图像处理都有很好的鲁棒性.     

A color value differentiation scheme for blind digital image watermarking

Multimedia Tools and Applications - In order to contribute to the security of medical image, we present in this paper a blind and robust watermarking technique that allows the integration of the...     

A novel image watermarking scheme based on amplitude attack

This paper presents a novel image watermark scheme based on the characteristics of amplitude attacks. First of all, the analysis of amplitude attacks is performed. Then the amplitude attacks are categorized into three types: positive attack, negative attack and random attack. Finally, based on these attack types, we design three corresponding detectors. The detectors remove the unreliable discrete cosine transform (DCT) coefficients in the attacked image so that only reliable coefficients are used for the extraction of the watermark embedded. The experimental results indicate that the proposed technique improves robustness significantly without sacrificing the false alarm rate.     

基于几何校正的双树复小波域彩色图像水印算法

为了使图像水印算法拥有更好的鲁棒性和不可感知性,以双树复小波变换(DTCWT)为基础,提出了一种新的彩色图像盲水印算法。本算法将彩色图像颜色空间由RGB转换到YIQ,选取亮度分量Y进行双树复小波变换,得到低频子带,然后将加密后的水印信息嵌入到低频子带中。在水印提取过程中,使用了新颖的基于四元数PHT的最小二乘支持向量(LS-SVM)几何校正方法。实验结果表明,本算法具有更好的鲁棒性和不可感知性。     

基于DWT-SVD域的彩色图像自适应水印算法

为了保护数字彩色图像版权,提出了一种结合离散小波变换(DWT)和矩阵奇异值分解(SVD)的彩色图像自适应水印算法。其主要设计思想是:先将原RGB彩色图像的各颜色分量进行小波分解;再将得到的中、低频带的小波系数与原水印图像分别进行奇异值分解,水印信息的奇异值重复嵌入到三通道中、低频带的小波系数奇异值中,且利用临界视觉阈值与奇异值之间的关系对水印嵌入强度作自适应调节,从而达到增强水印鲁棒性和确保水印透明性的目的。本算法适用于二值及灰度水印,在二值水印的提取过程中需设定一个提取阈值,以保证提取水印的完整性。仿真结果说明本算法对水印系统的透明性与鲁棒性作了较好的协调,是一种较稳健的算法。     

Geometrically invariant color image watermarking scheme using feature points

Geometric distortion is known as one of the most difficult attacks to resist. Geometric distortion desynchronizes the location of the watermark and hence causes incorrect watermark detection. In this paper,we propose a geometrically invariant digital watermarking method for color images. In order to synchronize the location for watermark insertion and detection,we use a multi-scale Harris-Laplace detector,by which feature points of a color image can be extracted that are invariant to geometric distortions. ...     

A new digital image watermarking scheme based on Schur decomposition

In this paper, we present a new digital watermarking scheme for ownership protection. The algorithm embeds the watermark in the Schur decomposition components of the cover image. We also show that this algorithm is noninvertible. Comparisons with other algorithms indicate that the proposed algorithm is robust against most common attacks including geometrical distortions and jpeg compression attacks. Simulations show that the performance of this algorithm outperforms the closely related singular value decomposition based algorithms. More specifically, the proposed algorithm is more robust and requires less number of computations. In addition, our algorithm does not suffer the false positive detection problem inherent in SVD based algorithms.     

基于混沌和BEMD分解的小波域彩色图像数字水印算法

提出了一种基于离散小波变换、混沌系统和二维经验模式分解的彩色图像数字水印算法。首先,对彩色载体图像的G通道进行一级小波分解,将其低频分量进行混沌位置置乱;然后将置乱后的低频分量进行二维经验模式分解,分解成5个基本模式分量和1个残差分量;最后,用水印信息代替第4个中低频基本模式分量实现信息嵌入。利用归一化互相关函数和峰值信噪比对算法进行评定,并对含水印的图像进行攻击。实验结果表明,该算法嵌入容量较大,且具有较好的透明性和鲁棒性。     

基于提升方案小波的半脆弱水印图像认证算法

在小波变换域内,将水印嵌入在特定的小波系数中,对图像带来的失真影响很小,同时可以准确地检测和篡改定位,因此目前实现认证的脆弱水印和半脆弱水印大多在小波域内.提出了一种使用提升小波变换的半脆弱水印方法.在原始宿主图像经过提升小波变换之后的低频子带,根据水印和小波系数的特征自适应地修改小波系数,嵌入过程实现了很好的不可见性和鲁棒性,实现了盲提取,并能准确地实现篡改的检测和定位.     

A secure reversible color image watermarking scheme based on LBP,lagrange interpolation polynomial and weighted matrix

Multimedia Tools and Applications - Secure reversible watermarking schemes are essential for image authentication and tamper detection in medical, military and government applications. In this...     

基于DCT的自适应图像盲水印算法

数字水印技术是多媒体信息安全领域的一个重要的研究课题.提出了一种基于DCT域的盲水印算法,该算法将图像经DCT变换后进行8×8分块,然后将二值水印嵌入到每一个图像分块的中频系数中.在嵌入过程中利用每一块的中频系数的性质,自适应的确定嵌入强度,从而保证了所嵌入的水印对一些常用的图像处理操作具有很强的鲁棒性.实验结果验证了提出方法的有效性.     

A blind double color image watermarking algorithm based on QR decomposition

In this paper, a novel blind image watermarking scheme based on QR decomposition is proposed to embed color watermark image into color host image, which is significantly different from using the binary or gray image as watermark. When embedding watermark, the 24-bits color host image with size of 512?×?512 is divided into non-overlapping 4?×?4 pixel blocks and each pixel block is decomposed by QR. Then, according to the watermark information and the relation between the second row first column coefficient and the third row first column coefficient in the unitary matrix Q, the 24-bits color watermark image with size of 32?×?32 is embedded into the color host image. In addition, the new element compensatory method is used in the upper-triangle matrix R for reducing the visible distortion. When extracting watermark, only the watermarked image is needed. Compared with other SVD-based methods, the proposed method does not have the false-positive detection problem and has lower computational complexity, that is, the average running time of the proposed method only needs 1.481403 s. The experimental results show that the proposed method is robust against most common attacks including JPEG compression, JPEG 2000 compression, low-pass filtering, cropping, adding noise, blurring, rotation, scaling and sharpening et al. Compared with some related existing methods, the proposed algorithm has stronger robustness and better invisibility.     

基于改进颜色空间的彩色图像双水印算法

基于保护图像原始特征信息和携带标识信息的多用途需求,提出一种彩色图像双水印算法.其中一个水印是图像特征,另一个水印是标识水印.首先,对图像进行Curvelet变换提取纹理特征;其次,对YCbCr改进型颜色空间Y$''Cb''Cr''$的$Y''$通道分块后进行DCT变换,用量化索引方式在每块DCT系数SVD变换后的最大奇异值上嵌入第1个纹理特征水印;再次,对Cb$''$和Cr$''$通道进行Curvelet变换,并对低频系数进行联合,根据能量分布自适应嵌入第2个水印图;然后,对嵌入水印后的3个通道频域系数进行逆变换得到空间图,并将该图转换到RGB空间得到含双水印的彩色图像;最后,对所提出算法的性能进行验证,并与相关算法通过对比的科学实验方法作比较,实验结果表明嵌入图像的双水印具有良好的不可见性和鲁棒性,特征水印能够对图像原始纹理特征进行有效的保护.     

基于可信赖第三方的鲁棒性的图像水印方案

图像水印技术主要是用来保护图像的版权。提出了一个鲁棒性的基于可信赖第三方的图像水印方案，这种方法有两大优点。方案中的水印和原图像是同一种类型，例如灰度级图像。方案满足水印技术的要求。由于引入了可信赖第三方，用户无法觉察和破坏图像中的水印。它能够抵抗各种图像改变算法的攻击，包括滤波、有损压缩和旋转等。