A Novel Color Watermarking Algorithm Based on Block SVD

Robust watermarking is a valuable methodology used in protecting the copyright and securing digital images. In this paper, new fractional-order multi-channel orthogonal exponent moments (MFrEMs) and their invariants to geometric transformations are derived for the first time. We utilized these highly accurate moments to construct a new robust watermarking algorithm for color images. This algorithm consists of three phases. First, the bits of the binary watermark scrambled by using a 1D Sine chaotic map. Second, the fractional-order MFrEMs are calculated from the host color image. Finally, a quantization process is performed, where the scrambled bits of the binary watermark embedded into the host color image. Various experiments were conducted to test the proposed watermarking algorithm and compare it with the existing robust watermarking algorithms for color images. The obtained results ensure the proposed robust watermarking algorithm's superiority over existing algorithms regarding the visual imperceptibility and robustness against various attacks.

Digital watermarking has been widely applied to solve copyright problems of digital media relating to illegal use or distribution. In the past few years, several gray-level image watermarking algorithms have been proposed, but few of them can be applied to color image. A digital watermarking algorithm for a color watermark embedded into a color host image, based on color space transform and IWT (Integer Wavelet Transform), is proposed. According to the Human Visual System peculiarity and quantizing the wavelet coefficient, Encrypted watermark is embedded adaptively into the luminance Y of the YIQ mode in IWT domain. The proposed algorithm allows extracting the watermark without the help of the original watermark and host image. Experimental results show that the embedded watermark is invisible and robust against common image processing.

Watermarking techniques have been proposed as an effective method to protecting the copyright of multimedia data. At present, a large proportion of the watermarking algorithms embed the grey image into the carrier image. In this paper, a watermarking algorithm for color images based on wavelet analysis is proposed. The algorithm scrambled the original watermark image in pretreatment, and used the wavelet transform to process the carrier image and the scrambled watermark image. Then the color watermarked image was embedded into the low-frequency discrete wavelet coefficient of the color carrier image. The experimental results demonstrate that the algorithm can assure the security of the watermark image, and the watermark image has good invisibility and strong robustness for common signal processing and attack.

This paper presents an algorithm by embedding a digital watermark into an original color image. Considering the characteristics of HVS, YUV color space is employed, this algorithm presents a new adaptive digital audio watermarking based on discrete cosine transform. The result of the experiment shows that the proposed algorithm has good robustness against various image processing and attacks, good invisibility and stability.

A watermarking algorithm for color images was proposed, which is resistant with the JPEG lossy compression and can locate tampered regions. Through a certain mathematical operation with an Arnold scrambled key image and low DCT coefficients of the original image, a chaotic initial value can be obtained, and then the watermark information can be generated by iterating the Kent chaotic maps. Corresponding to the applicable block index of the image, the watermark information is embedded in the specific positions of the middle DCT coefficients to get the watermarked image. Experimental results show that the proposed algorithm has a strong robustness against JPEG lossy compression and can keep false alarm ratios 0 when the quality factor of the JPEG compression is beyond 35, moreover, it can detect the accurate locations of the malicious tampers.

In this paper, we propose a novel medical color image digital watermarking algorithm, which can realize watermark capacity, transparency and robustness effective compromise. We encrypt the watermark image by Arnold Transform at first and then take it into a random sequence. The principal component of medical image is divided into some sub-blocks with 4×4 and each block is transformed by DCT. One bit of watermark is embedded by comparing the size of specific DCT coefficients in the adjacent sub-blocks. Watermark can be extracted without the original medical image. The experimental results show that the digital watermarking algorithm has a high transparency and big capacity as well as certain robustness.

In this paper, we propose a novel medical color image digital watermarking algorithm, which can realize watermark capacity, transparency and robustness effective compromise. We encrypt the watermark image by Arnold Transform at first and then take it into a random sequence. The principal component of medical image is divided into some sub-blocks with 4×4 and each block is transformed by DCT. One bit of watermark is embedded by comparing the size of specific DCT coefficients in the adjacent sub-blocks. Watermark can be extracted without the original medical image. The experimental results show that the digital watermarking algorithm has a high transparency and big capacity as well as certain robustness.

Together with the rapid growth of Internet service, copyright violation problems, such as unauthorized duplication and alteration of digital materials, have increased considerably (Langelaar et al., 2001). Therefore copyright protection over the digital materials is a very important issue that requires an urgent solution. The watermarking is considered as a viable technique to solve this problem. Until now, numerous watermarking algorithms have been proposed. Most of them are image watermarking algorithms and relatively few of them are related with video sequences. Although image watermarking algorithms can be used to protect the video signal, generally they are not efficient for this purpose, because image watermarking algorithms does not consider neither temporal redundancy of the video signal nor temporal attacks, which are efficient attacks against video watermarking (Swanson et al., 1998). Generally, in the watermarking schemes for copyright protection, the embedded watermark signal must be imperceptible and robust against common attacks, such as lossy compression, cropping, noise contamination and filtering (Wolfgang et al., 1999). In addition, video watermarking algorithms must satisfy the following requirements: a blind detection, high speed process and conservation of video file size. The blind detection means that the watermark detection process does not require original video sequence, and the temporal complexity of watermark detection must not affect video decoding time. Also the file size of video sequence must be similar, before and after watermarking. Due to the redundancy of the video sequence, some attacks such as frame dropping and frame averaging can effectively destroy the embedded watermark, without cause any degradation to the video signal. A design of an efficient video watermarking algorithm must consider this type of attacks (Wolfgang et al., 1999). Basically, video watermarking algorithms can be classified into three categories: watermarking in base band (Wolfgang et al., 1999; Hartung & Girod 1998; Swanson et al., 1998; Kong et al., 2006), watermarking during video coding process (Liu et al., 2004; Zhao et al., 2003; Ueno 2004; Noorkami & Mersereau 2006) and watermarking in coded video sequence (Wang et al., 2004; Biswas et al., 2005; Langelaar & Lagendijk 2002). In the base band technique, the watermarking process is realized in uncompressed video stream, in which almost all image watermarking algorithms can be used, however generally computational complexity for watermark embedding and detection is considerably high for

Robust watermarks are evaluated in terms of image fidelity and robustness. We extend this framework and apply reliability testing to robust watermark evaluation. Reliability is the probability that a watermarking algorithm will correctly detect or decode a watermark for a specified fidelity requirement under a given set of attacks and images. In reliability testing, a system is evaluated in terms of quality, load, capacity and performance. To measure quality that corresponds to image fidelity, we compensate for attacks to measure the fidelity of attacked watermarked images. We use the conditional mean of pixel values to compensate for valumetric attacks such as gamma correction and histogram equalization. To compensate for geometrical attacks, we use error concealment and perfect motion estimation assumption. We define capacity to be the maximum embedding strength parameter and the maximum data payload. Load is then defined to be the actual embedding strength and data payload of a watermark. To measure performance, we use bit error rate (BER) and receiver operating characteristics (ROC) and area under the curve (AUC) of the ROC curve of a watermarking algorithm for different attacks and images. We evaluate robust watermarks for various quality, loads, attacks, and images.

Medical images stored in a hospital system are generally confidential and integrated and require strict security. However, medical information stored on digital medical imaging systems, as well as picture archiving and communication systems (PACS), are vulnerable to attack when the data are transferred over wireless or wired communication networks. To solve this problem, a watermarking algorithm for medical images is proposed using a bit threshold map based on just noticeable distortion (JND) in the discrete cosine transform (DCT) method. The low-frequency component comprises a considerable amount of the signal energy for most images. As a result, it has a crucial effect on the image quality. Therefore, in this paper, the proposed algorithm embeds watermarks based on the low-frequency components of the image, such as the DC coefficient of the DCT. When watermarks are embedded in a low frequency area, the subjective image quality is often degraded. To compensate for the degradation of the imperceptibility of the watermarking system, which results from embedding watermarks in the low-frequency component, this research considers the human visual system. In addition, the embedding strength of the JND value is used to improve the watermarking imperceptibility. We applied the proposed watermarking algorithm to a variety of medical images using a computer simulation. The algorithm's performance was verified using a variety of attacks for eliminating watermarks. The simulation results show that the proposed algorithm robustly provides protection against a variety of possible attacks.

Four-scanning attack on hierarchical digital watermarking method for image tamper detection and recovery

A coding layer robust reversible watermarking algorithm for digital image in multi-antenna system

In this paper, a robust algorithm of digital image watermarking based on discrete wavelet transform is introduced It uses blind watermarking technique. Digital image watermarking is one such technology that has been developed to protect digital images from illegal manipulations. In particular, digital image watermarking algorithms which are based on the discrete wavelet transform have been widely recognized to be more prevalent than others. This is due to the wavelets' excellent spatial localization, frequency spread, and multi-resolution characteristics, which are similar to the theoretical models of the human visual system.

Infrared images often involve trade secrets. In order to protect the information security of infrared images, using a robust watermarking algorithm based on infrared images is a fitting solution. Recently, many effective visible and infrared image fusion (VIF) algorithms have been proposed in medicine, biology, and geology. Robust watermarking algorithms can resist mild conventional attacks, and with the progress of science and technology, algorithmic robustness against novel attacks such as screen shooting and print shooting has also become a research hotspot. However, VIF‐based image watermarking algorithms are still scarce. It is important to investigate a robust watermarking algorithm that can resist VIF attacks. Herein, an autoencoder against infrared fusion attacks is proposed based on various subnetworks: CRDnet (Convolutional Residual Dense Network). CRDnet includes encoders and decoders based on residual and dense structures, a fusion network robust to 12 VIF algorithms, and predictors for predicting watermarked infrared images. The encoder and decoder also incorporate preprocessing steps, attention mechanisms, and activation functions suitable for infrared images. The experimental results demonstrate that the bit error rate of CRDnet is reduced by at least ≈4% compared to common autoencoders. The peak signal‐to‐noise ratio of watermarked images is also almost always greater than 38 dB.

Recently watermarking algorithms of digital images based on singular value decomposition (SVD) have been proposed. Most SVD-based watermarking techniques use singular values as the embedding watermark information. These SVD-based techniques are advantageous for watermarking images since slight changes in the singular values do not significantly affect the image quality. However, it has been reported that these SVD-based watermarking algorithms, as implemented, suffer from a very high probability of false positive detections of watermarks. The false positive detection vulnerability of two recent SVD-based watermarking schemes is exposed. Two solutions are proposed to mitigate this vulnerability without changing the design principle of these watermarking algorithms.