一种自嵌入盲检测鲁棒数字水印算法

为了实现鲁棒水印算法的完全盲检测,提出一种自嵌入盲检测鲁棒数字水印算法。该算法对原始图像分块子图进行小波提升变换得到低频近似分量,对近似分量作非负矩阵分解得到可近似表示子块图像的基矩阵和系数矩阵;在此基础上将系数矩阵量化得到鲁棒水印序列,最后鲁棒水印序列自适应量化嵌入原始图像低频自带近似分量。实验结果表明,该方案对常见信号处理具有很强的鲁棒性,实现了鲁棒水印序列完全盲检测。     

A blind medical image watermarking: DWT-SVD based robust and secure approach for telemedicine applications

Multimedia Tools and Applications - In this paper, a blind image watermarking scheme based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. In this scheme,...     

A novel hybrid of DCT and SVD in DWT domain for robust and invisible blind image watermarking with optimal embedding strength

To optimize the tradeoff between imperceptibility and robustness properties, this paper proposes a robust and invisible blind image watermarking scheme based on a new combination of discrete cosine transform (DCT) and singular value decomposition (SVD) in discrete wavelet transform (DWT) domain using least-square curve fitting and logistic chaotic map. Firstly cover image is decomposed into four subbands using DWT and the low frequency subband LL is partitioned into non-overlapping blocks. Then DCT is applied to each block and several particular middle frequency DCT coefficients are extracted to form a modulation matrix, which is used to embed watermark signal by modifying its largest singular values in SVD domain. Optimal embedding strength for a specific cover image is obtained from an estimation based on least-square curve fitting and provides a good compromise between transparency and robustness of watermarking scheme. The security of the watermarking scheme is ensured by logistic chaotic map. Experimental results demonstrate the better effectiveness of the proposed watermarking scheme in the perceptual quality and the ability of resisting to conventional signal processing and geometric attacks, in comparison with the related existing methods.     

A new robust reference logo watermarking scheme

In this paper, a new yet simple reference logo watermarking scheme based on fractional Fourier transform (FrFT) and singular value decomposition (SVD) is proposed. The core idea of the proposed scheme is to segment host image into non-overlapping blocks by the means of Hilbert space filling curve and a reference image is formed by considering Human visual system (HVS). First, reference image is transformed into FrFT domain and embedding is done by modifying singular values of the reference image using singular values of watermark. After embedding, modified reference image is segmented into blocks and these modified blocks are mapped into their original places for constructing watermarked image. For extraction, a reliable watermark extraction scheme is proposed. The experimental results demonstrate better visual imperceptibility and resiliency of the proposed scheme against intentional or un-intentional variety of attacks.     

A new aspect in robust digital watermarking

Generally, in watermarking scheme the size of the watermark is very small when compare to host image. On the contrary, this is an attempt in which a new watermarking scheme is presented where the size of host image is very small when compare with watermark image. The core idea of the proposed scheme is to scale up the size of host image equal to the size of watermark via over-sampling and then decompose it using stationary wavelet transform. A gray scale watermark is embedded in the low frequency sub-band at the finest level using singular value decomposition. To prevent ambiguity and enhance the security, a binary watermark is also embedded in loss-less manner. Finally, a reliable watermark extraction scheme is developed for extracting both the watermarks. The experimental results demonstrate better visual imperceptibility and resiliency of the proposed scheme against intentional or un-intentional variety of attacks.     

小波域中的鲁棒性盲水印算法

提出了自适应的鲁棒性图像水印方案。用密钥选择嵌入的位置,增加水印的安全性,并只对有嵌入要求的图像块进行离散小波变换,这样算法的计算复杂度只与水印容量有关,与宿主图像无关,相对减少了计算的复杂度。在水印嵌入过程中,对相应的有嵌入要求的图像块进行分类来决定不同的嵌入强度,达到了自适应的嵌入要求。为了更好地增加方案的鲁棒性,采用基因算法对阈值进行了优化。实验结果表明,此方案具有很好的透明性,对通常的图像处理具有很好的鲁棒性。     

自嵌入全盲鲁棒水印量化算法

为了提高图像水印的实用性,提出了一种自嵌入全盲鲁棒水印算法。首先,对原始图像进行DWT,将小波低频子带分成互不重叠的子块,对每个子块进行DCT,通过比较各个子块的直流系数与所有子块直流系数的均值之间的大小关系来产生特征水印序列,利用分段Logistic混沌序列对特征水印进行加密;然后,将加密后的特征水印序列通过奇偶量化规则自嵌入到原始图像小波低频子带每个子块的DCT低频系数中;最后,进行IDCT合成和IDWT产生含水印图像。该算法通过结合自嵌入加密的特征水印序列和盲提取认证水印序列达到全盲检测。实验结果表明,该算法对抵抗添加噪声、JPEG压缩及高斯低通滤波等常见的图像处理攻击均具有很强的鲁棒性。     

A key points-based blind watermarking approach for vector geo-spatial data

This paper presents a blind watermarking approach to protecting vector geo-spatial data from illegal use. By taking into account usability, invisibility, robustness, and blindness, the approach firstly determines three feature layers of the geo-spatial data and selects the key points from each layer as watermark embedding positions. Then it shuffles the watermark and embeds it in the least significant bits (LSBs) of the coordinates of the key points. A similar process for selecting the feature layers and the key points in the watermark embedding process is carried out to detect the watermark followed by obtaining the embedded watermark from the LSBs of the coordinates of the key points. Finally, the similarity degrees of three versions of the watermark from three feature layers are calculated to check if the data contains the watermark. Our experiments show that the method is rarely affected by data format change, random noise, similarity transformation of the data, and data editing.     

A new robust reference watermarking scheme based on DWT-SVD

This paper presents a new semi-blind reference watermarking scheme based on discrete wavelet transform(DWT) and singular value decomposition(SVD) for copyright protection and authenticity. We are using a gray scale logo image as watermark instead of randomly generated Gaussian noise type watermark. For watermark embedding, the original image is transformed into wavelet domain and a reference sub-image is formed using directive contrast and wavelet coefficients. We embed watermark into reference image by modifying the singular values of reference image using the singular values of the watermark. A reliable watermark extraction scheme is developed for the extraction of watermark from distorted image. Experimental evaluation demonstrates that the proposed scheme is able to withstand a variety of attacks. We show that the proposed scheme also stands with the ambiguity attack also.     

DWT-SVD域全盲自嵌入鲁棒量化水印算法

引入自嵌入技术提出一种DWT-SVD域全盲鲁棒量化水印算法,只需借助攻击图像进行版权认证。对原始图像先进行DWT,将小波低频子带分成互不重叠的子块,对每个子块进行SVD,通过对比相邻两个子块最大奇异值的大小关系产生特征水印序列,然后将选定的自嵌入特征水印序列通过奇偶量化规则自嵌入原始图像小波低频子带每个子块的最大奇异值,最后进行SVD合成和IDWT产生含水印图像。算法具有良好的不可见性和安全性,并且通过结合自嵌入特征水印序列和盲提取认证水印序列达到全盲检测。实验结果表明,算法具有较强的抵抗添加高斯噪声、添加椒盐噪声、高斯低通滤波、中值滤波、剪切、JPEG压缩和混合攻击的鲁棒性。     

A robust blind hybrid image watermarking scheme in RDWT-DCT domain using Arnold scrambling

Multimedia Tools and Applications - To compromise between imperceptibility and robustness property of robust image watermarking technique, a RDWT-DCT based blind image watermarking scheme using...     

Framework for robust blind image watermarking based on classification of attacks

With the widespread internet usage, digital contents are easily distributed throughout the world. To eliminate concerns of producers and owners of digital contents, watermarking techniques are extensively being used. Robustness against intentional and unintentional attacks is a major quality of watermarking systems. Since different attacks tend to target different parts of the frequency spectrum, in this paper we propose a framework for blind watermarking which determines the type of attack that the image has gone through before extracting the watermark. Within this framework, we propose an attack classification method to identify the region of the frequency spectrum that is less damaged. The watermark which is redundantly spread throughout the spectrum can be extracted from the less damaged regions. Experimental results show functionality of the framework by producing better results in comparison with well-known blind watermarking techniques.     

GPU-accelerated blind and robust 3D mesh watermarking by geometry image

The prevalence of cheap and powerful consumer level graphics accelerated hardware introduces a significant growth of 3D applications. In this paper, we have proposed a GPU-accelerated blind and robust watermarking approach to the 3D polygon meshes on the basis of the geometry image transform and image watermarking, which performs watermark embedding and detection on the basis of the geometry image derived from a spherical parametrisation of the input mesh with the help of massive-parallel processing power of the GPUs on the display card. The experimental results show that our approach is successful in at least two aspects. First, the watermark is robust, the embedded watermark survives from common geometric attacks, cropping, simplification, and re-meshing attacks. Second, with the help of parallel computations on the GPUs, the embedding and detection process is extremely fast.     

一种基于zigzag扫描的DCT鲁棒数字盲水印算法

针对提高水印算法的鲁棒性进行研究,提出一种基于zigzag扫描的DCT鲁棒数字盲水印算法。算法对分块后DCT域的中、低频系数进行zigzag扫描得到一维数列,利用每个数列数学范数比值和量化索引调制原理实现数字水印的嵌入,然后通过最小距离公式对水印提取。与其他算法相比,实验结果显示算法能够抵抗多种攻击,具有较好的透明性与鲁棒性。水印提取过程不需要原载体图像,实现水印信息盲提取。     

Tetrolet变换和SVD结合的盲检测稳健数字水印嵌入策略

提出了一种Tetrolet变换和奇异值分解(SVD)相结合的图像盲检测稳健数字水印算法。该算法先对二值水印图像进行双因子混沌加密预处理;对原始载体图像进行二级Tetrolet变换,并将二层低频子带系数进行分块SVD分解;最后将加密的水印信息量化嵌入SVD最大系数中。水印检测时,无需原始载体图像和原始水印图像的参与,实现水印信息盲提取,提高数字水印系统的实用性。仿真实验结果表明,在保证水印安全性和不可感知性的基础上,该算法对常规图像处理、几何攻击等均具有较好的稳健性。     

High-quality blind watermarking in halftones using random toggle approach

This paper presents a blind watermarking method for embedding large data into halftone images. Watermarking in ready-to-print halftones is desirable in printer applications such as authentication and document/image security. It is challenging to embed large information into halftones, while maintaining high image quality. In this paper, we first review a series of halftone watermarking methods that embed data by using Embedding Toggle (ET) in the selected positions. We find that such ET-based methods have two shortcomings: 1) the image quality is limited because of the unknown input data and randomly selected embedding positions, and 2) the selected embedding positions must be recorded to retrieve the hidden data. To tackle the above disadvantages, this study makes two improvements. First, we propose a random toggle approach, in which the embedding positions are movable. Therefore, after the data are embedded, each dot can still be shifted to the most appropriate position to improve the image quality. Second, a self-decodable even/odd parity checking scheme is proposed to embed one bit information in each image block. We also propose a new search strategy, called Swap-Only Block-Based (SOBB) search. By integrating SOBB search with the direct binary search method, the image quality can be greatly improved without damaging the hidden data. From experimental results, the proposed method demonstrated sufficient robustness and excellent image quality.     

Hybrid blind robust image watermarking technique based on DFT-DCT and Arnold transform

Multimedia Tools and Applications - In this paper, a robust blind image watermarking method is proposed for copyright protection of digital images. This hybrid method relies on combining two...     

DWT-SVD and DCT based robust and blind watermarking scheme for copyright protection

In this article, a new DWT-SVD and DCT with Arnold Cat Map encryption based robust and blind watermarking scheme is proposed for copyright protection. The proposed scheme solves the most frequently occurring watermarking security problems in Singular Value Decomposition (SVD) based schemes which are unauthorized reading and false-positive detection. This scheme also optimizes fidelity and robustness characteristics. The grey image watermark splits into two parts using four bits MSBs and four bits LSBs of each pixel. Discrete Cosine Transform (DCT) coefficients of these MSBs and LSBs values are embedded into the middle singular value of each block having size 4 × 4 of the host image’s one level Discrete Wavelet Transform (DWT) sub-bands. The reason for incorporating Arnold Cat Map in the proposed scheme is to encode the watermark image before embedding it in the host image. The proposed scheme is a blind scheme and does not require the choice of scaling factor. Thus, the proposed scheme is secure as well as free from the false positive detection problem. The proposed watermarking scheme is tested for various malicious and non-malicious attacks. The experimental results demonstrate that the scheme is robust, imperceptible and secure to several attacks and common signal processing operations.     

A novel blind watermarking approach for medical image authentication using MinEigen value features

Developing new watermarking approaches that consider special features of medical images become increasingly necessary. This paper proposes a new watermarking approach to ensure medical images authenticity, using MinEigen value features, chaotic sequence, and Quantization Index Modulation (QIM) in the spatial domain. The idea is to choose the 3?×?3 non overlapping blocks around MinEigen values points, then embed the watermark bits in these blocks using a novel blind way based on chaotic sequence and QIM. The proposed technique is purely blind and fast in terms of execution time. Experimental results demonstrate that the proposed approach is robust against all DICOM JPEG compression attacks while keeping high imperceptibility.