Introducing a new method robust against crop attack in digital image watermarking using two-step sudoku

A gray-level intensity image can be employed as a host image for hiding a watermark image to protect information security. Past research works demonstrate that a gray-level hidden image can be embedded into the host image by a digital phase-only holography method. However, the fidelity of retrieved watermark image from the host image is not very satisfactory and the host image quality is degraded due to the insertion of external data bits, especially when observers focus on the saliency regions in the host image. To address this problem, we propose a steganography method based on digital holography and the saliency map of the host image. First, we calculate the hidden capacity (number of bits to be replaced) for each host image pixel based on the weighted sum of pixel intensity and saliency value. Next, a multilevel phase-only digital hologram of the watermark image will be calculated by the Gerchberg–Saxton method under the constraint of the hidden capacity of host image. Finally, we embedded the multilevel phase-only digital hologram into the host image by replacing a corresponding number of bits in each pixel. In this way, the host image can preserve good image fidelity for its saliency regions even if we hide a large amount of digital hologram data into the host image. The experimental results show that the quality of retrieved watermark image from the host image and the quality of saliency regions in the watermarked host image, in our proposed scheme, are superior to the state-of-the-art works reported.

Digital image watermarking is a process of embedding a target image to the host image. A target image is known as watermark image. A host image is the image on which watermarking is done. Digital Image Watermarking is used for copyright protection, authenticity determination, ensuring tamper-resistance. This paper reviews various different watermarking techniques on homomorphic encrypted images.

A digital watermark is an invisible mark embedded in a digital image which may be used for copyright protection. This paper proposes that Fourier-Mellin transform-based invariants can be used for digital image watermarking. The embedded marks may be designed to be unaffected by any combination of rotation, scale and translation transformations. The original image is not required for extracting the embedded mark.

ABC optimized secured image watermarking scheme to find out the rightful ownership

Digital watermarking has been widely studied as a method of protecting the intellectual property rights of digital images, which are high value-added contents. Recently, studies implementing these techniques with neural networks have been conducted. This paper also proposes a neural network to perform a robust, invisible blind watermarking for digital images. It is a convolutional neural network (CNN)-based scheme that consists of pre-processing networks for both host image and watermark, a watermark embedding network, an attack simulation for training, and a watermark extraction network to extract watermark whenever necessary. It has three peculiarities for the application aspect: The first is the host image resolution’s adaptability. This is to apply the proposed method to any resolution of the host image and is performed by composing the network without using any resolution-dependent layer or component. The second peculiarity is the adaptability of the watermark information. This is to provide usability of any user-defined watermark data. It is conducted by using random binary data as the watermark and is changed each iteration during training. The last peculiarity is the controllability of the trade-off relationship between watermark invisibility and robustness against attacks, which provides applicability for different applications requiring different invisibility and robustness. For this, a strength scaling factor for watermark information is applied. Besides, it has the following structural or in-training peculiarities. First, the proposed network is as simple as the most profound path consists of only 13 CNN layers, which is through the pre-processing network, embedding network, and extraction network. The second is that it maintains the host’s resolution by increasing the resolution of a watermark in the watermark pre-processing network, which is to increases the invisibility of the watermark. Also, the average pooling is used in the watermark pre-processing network to properly combine the binary value of the watermark data with the host image, and it also increases the invisibility of the watermark. Finally, as the loss function, the extractor uses mean absolute error (MAE), while the embedding network uses mean square error (MSE). Because the extracted watermark information consists of binary values, the MAE between the extracted watermark and the original one is more suitable for balanced training between the embedder and the extractor. The proposed network’s performance is confirmed through training and evaluation that the proposed method has high invisibility for the watermark (WM) and high robustness against various pixel-value change attacks and geometric attacks. Each of the three peculiarities of this scheme is shown to work well with the experimental results. Besides, it is exhibited that the proposed scheme shows good performance compared to the previous methods.

Watermarking is a technology that complements cryptography by embedding imperceptible signals in work. Information hiding techniques have recently become important in a number of application areas. Digital audio, video and images are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice that helps to prevent unauthorized copying directly. One approach is to introduce an invisible image known as digital watermark, into an image sequence. This paper presents secured algorithms for embedding digital watermarks into images. The proposed method performs imperceptible watermarking of images in frequency domain. The watermark is embedded in the DWT and DCT domain of an image in a multi-resolution way. In the decoding phase, once the watermark is extracted from the watermarked image, certain performance measures such as peak signal to mean noise ratio (PSNR) and correlation are calculated. Different types of attacks have been applied to the watermarked image to test the robustness of the applied technique and for each case, PSNR and correlation are calculated. Even though DWT method gives better results when compared to DCT, performances of both methods are good.

Recently, works are completely based on the internet, so authentication is required to protect the content of the data because owner never wants to degrade the quality of his data. Information hiding via digital watermarks for the multimedia data is the compatible way to provide the protection of data. Watermarks are imperceptible and it is predefined pattern inserting into multimedia data to protect or authenticity. The watermark indicates that data is containing a copyright or not. Many digital watermarking algorithms have been proposed in spatial and transform domain. The performance of the digital watermarking schemes is evaluated as tradeoffs between images embedded on it, robustness against attacks and embedding induced distortions. This work provides Digital image watermarking using Fractional Fourier transform via image compression for better results comparatively previous techniques of information hiding.

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.

The main objectives of digital image watermarking schemes are to provide acceptable level of both imperceptibility and robustness for wide variety of host and watermark images. To support watermarking scheme in accomplishing these objectives, suitable watermark strength is identified in the form of scaling factor using Dynamic-PSO (DPSO) for colored images. A non-blind, DWT-SVD-based watermarking scheme is used to embed watermark in host image. Results achieved through DPSO are compared with PSO and other widely accepted variants of PSO. Experiment results demonstrate that performance of underline watermarking scheme when used with DPSO is better than other variants of PSO.

Presented is an efficient watermarking scheme using Particle Swarm Optimization (PSO) to watermark host fingerprint images with their corresponding facial images in the Discrete Cosine Transform (DCT) domain. PSO is used to find the best DCT coefficients’ locations in the host image where the facial image data can be embedded, so that the distortion produced in the host image is minimum. The objective function for PSO is formulated in terms of the Structural Similarity Index (SSIM) and the Orientation Certainty Level Index (OCL) so as to base it on the simple visual effect of the human visual perception capability and correct minutia prediction ability. The results exhibit better watermarked image quality while retaining the feature set of the original fingerprint. Moreover, the proposed technique is robust so that the extraction of watermark is possible even after the watermarked image is exposed to attacks. As a result, at the receiver’s end, the watermarked fingerprint image and the extracted facial image can be verified for a secure and accurate biometric based personal authentication.

Due to the rise in many industrial environment applications involving distributed networked collaborative intelligent measurement systems, intelligent monitoring and multi-sensor information exchange of private information, digital image information security and hidden image authentication, tampering detection, correction, and automatic intelligent self-recovery have become critical concerns. Towards that end, there is a need for more secure, efficient, and robust-to-unauthorized-tampering digital image watermarking, information hiding and authentication schemes. In our prior work, we introduced non-blind watermarking schemes where the carrier and watermark images are available at the receiver's end. We also proposed a double-blind scheme where both the carrier and the watermark images are not available at the receiver's end, but at the expense of possible lower pixel tampering, authentication and automatic intelligent self-correction ability. This paper proposes a blind wavelet-based, high capacity, secure digital watermarking and information hiding scheme with higher tampering localization and authentication that nullifies the need to have the carrier image available at the receiving end. The proposed scheme also increases robustness to image authentication and automatic self-recovery and correction compared to our prior double-blind scheme. The scheme is high capacity and sustains hiding secret hidden and watermarking images of the same full size as an arbitrary-sized carrier image. One of the benefits of the blind watermarking scheme is that it allows usage of varying and arbitrary carrier images that are unknown and unavailable anywhere, including the receiver's end. This is to prevent hackers' recognition of a familiar carrier image and their potential unauthorized tampering. Here, in this paper, two grayscale images are inserted in a colored carrier image. Here the watermark image is used for authentication and tamper localization. The second image is used as ownership or encoded secret hidden message image. The Arnolds Transform is used to introduce added security to a hidden image. The proposed scheme uses an embedded correction matrices mechanism for the extracted hidden information self-recovery from various tampering and digital attacks by unauthorized hackers.

Research in digital watermarking has evolved rapidly in the current decade. This evolution brought various different methods and algorithms for watermarking digital images and videos. Introduced methods in the field varies from weak to robust according to how tolerant the method is implemented to keep the existence of the watermark in the presence of attacks. Rotation attacks applied to the watermarked media is one of the serious attacks which many, if not most, algorithms cannot survive. In this paper, a new automatic rotation recovery algorithm is proposed. This algorithm can be plugged to any image or video watermarking algorithm extraction component. The main job for this method is to detect the geometrical distortion happens to the watermarked image/images sequence; recover the distorted scene to its original state in a blind and automatic way and then send it to be used by the extraction procedure. The work is limited to have a recovery process to zero padded rotations for now, cropped images after rotation is left as future work. The proposed algorithm is tested on top of extraction component. Both recovery accuracy and the extracted watermarks accuracy showed high performance level.

Image watermarking plays a vital role in providing protection from copyright violation. However, conventional watermarking techniques typically exhibit trade-offs in terms of image quality, robustness and capacity constrains. More often than not, these techniques optimize on one constrain while settling with the two other constraints. Therefore, in this paper, an enhanced saliency detection based watermarking method is proposed to simultaneously improve quality, capacity, and robustness. First, the enhanced structured matrix decomposition (E-SMD) is proposed to extract salient regions in the host image for producing a saliency mask. This mask is then applied to partition the foreground and background of the host and watermark images. Subsequently, the watermark (with the same dimension of host image) is shuffled using multiple Arnold and Logistic chaotic maps, and the resulting shuffled-watermark is embedded into the wavelet domain of the host image. Furthermore, a filtering operation is put forward to estimate the original host image so that the proposed watermarking method can also operate in blind mode. In the best case scenario, we could embed a 24-bit image as the watermark into another 24-bit image while maintaining an average SSIM of 0.9999 and achieving high robustness against commonly applied watermark attacks. Furthermore, as per our best knowledge, with high payload embedding, the significant improvement in these features (in terms of saliency, PSNR, SSIM, and NC) has not been achieved by the state-of-the-art methods. Thus, the outcomes of this research realizes a trade-off independent image watermarking method, which is a first of its kind in this domain.

There is a huge resource of data available on the internet which one can access without realizing that the person is even authorized to access it or not. The hard work of the original resource person can easily be compromised. Digital watermarking is an answer to overcome this issue. This paper introduces a hybrid of LSB and DCT techniques, LSB(Least Significant Bit) and DCT(Discrete Cosine Transformation). The paper studies the two techniques along with the proposed technique and a comparison is drawn between the three based on MSE and PSNR values obtained. The introduced hybrid technique performs better in comparison to DCT and LSB. The MSE calculated was 64% better than LSB and 60% better than DCT resultantly PSNR is also observed to be better than LSB and DCT.

The growth of network multimedia systems has expanded the demand for image copyright protection. Digital watermark is one approach which is often used for image copyright protection. However, there are limitations of robustness and confidentiality in the common digital watermarking algorithms to resist print-scan attacks. In this paper, a new method combining zero watermarking, blind watermarking and Arnold scrambling is proposed. The zero-watermarking algorithm in DCT low-frequency region avoids the limitation of watermarking capacity to a certain extent. And it has a certain degree of stability and adaptability as well as a strong anti-interference ability to the geometric attacks. In the intermediate-frequency region, the blind watermarking algorithm is used to embed the scrambling information of the watermark and it is robust. With such multilayer enciphering, the confidentiality of the watermark is improved. The whole method has made great progress in the resistance of the geometric attacks and confidentiality of watermark. It's proved that the method is an applicable method against print-scan attacks. It has a certain reference value to the study of digital image watermark.