Digital color image watermarking in wavelet domain

In this paper, the spread spectrum watermarking in wavelet domain is optimised by using a number of techniques to make it more efficient when executed by a platform running on mobile devices. The proposed techniques can be executed efficiently and consume less computational and power resources as compared to the conventional spread spectrum-based watermarking. The proposed technique represents binary bits in the watermark using symbols, wherein each symbol represents at least 2 binary bits. A symbol is then mapped into a pseudo noise sequence and embedded in the digital image. Our analytical results show that our schemes reduce the number of operations required for watermarking by ∼50%, while our experimental results show that our schemes save about ∼59 and ∼67% in processing time and energy consumption, respectively.

Image watermarking in wavelet domain has been emerged as an interesting area of research. However, classical wavelet transform, like DWT, lacks in providing directional information and is shift sensitive. These limitations can be overcome with the use of NSCT (Nonsubsampled contourlet transform), which is shift invariant and provides rich directional information. Therefore, in this work, we propose NSCT based image watermarking using MSVD (Multiresolution singular value decomposition). High directionality of NSCT provides better reconstruction of watermarked images, whereas MSVD provides invariance against geometrical attacks. Experiments have been performed over benchmark datasets. Qualitative and quantitative analysis in terms of PSNR (Peak signal to noise ratio) and CC (Correlation coefficients) shows the effectiveness of the proposed approach.

The massive spreading of broadband networks and new developments in digital technology has made ownership protection and authorisation of digital multimedia a very important issue. The reason is the availability of powerful tools for editing, lossless copying and transmission of digital multimedia such as images. Image watermarking is now an effective solution for the problem of authentication and protection of copyrighted image content. In this paper, discrete wavelet transform DWT-based watermarking technique is proposed in which mean energy of the each of 32 × 32 block in the CH and CV subbands is calculated and range of coefficients that exceed the mean energy of the block are selected for watermark embedding. Watson perceptual distortion control model is considered to keep the perceptual quality of the image and genetic programming GP is used to provide optimum watermarking level for the selected coefficients. The results show that there is almost no difference between original and watermarked image demonstrating key feature of imperceptibility. The technique has been tested and proves to be effective against a set of malicious attacks.

In the current digital era, patient data in the form of digital medical images in several hospitals are widely used. There are two important thin to use of digital medical images namely the ownership authority (integrity control) and the authenticity of the image (authentication), because digital medical images are very easily manipulated. To maintain the authority of ownership, it needs robust watermarking techniques in which the embedded data is not easily damaged if the image has been manipulated. Meanwhile, to detect the authenticity of the image, it needs fragile watermarking technique in which the embedded data is easily damaged if the image has been manipulated. In this paper, we implement Reed-Solomon code for robust watermark in wavelet domain and SHA-256 for fragile watermark in Hash Block Chaining. The proposed multiple watermarks can be implemented simultaneously on an image so that the integrity control and authenticity of the image detection can be applied at once.

An SVD-based image watermarking in wavelet domain using SVR and PSO

This scheme describes a procedure that uses the motion characteristics of the videos to calculate the embedding tolerance for imperceptible video watermarking in wavelet domain. This procedure exploits the perceptual properties of HVS and motion content of video sequence adoptively calculating the embedding tolerance of watermark in order to improve the imperceptibility of watermarking according to the content of video. The experiment results indicate that this method can effectively reduce the degradation in the video quality.

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.

In this paper, we propose a digital image watermarking scheme using Arnold transform. To implement this, a scrambled binary image is embedded into the coefficient of host images via Lifting wavelet transform. Then inverse wavelet transform is applied to get the watermarked image. We have applied to watermark in the transform domain instead of the spatial domain. This is since in a spatial domain the pixels of the cover image is directly manipulated, in contrast with transform domain where the coefficient of pixels is modified after applying different transformation technique that ultimately increases imperceptibility of the scheme. Moreover, nowadays most of the images are compressed in wavelet domain like JPEG 2000. Another important feature of the proposed algorithm is the Arnold scrambling technique which increases the security of the scheme. It is difficult for the attacker to derive the original watermark as well as retrieve the cover image. The proposed digital watermarking system is tested over a large number of standard grayscale (512×512) benchmark images to provide good imperceptibility and robustness. In our case, we have seen that the proposed technique offers the average value of peak signal-to-noise ratio (PSNR), Structural Similarity Index (SSI) before decoding and after decoding are 49.93, 0.97, 51.72 and 0.976721 respectively. The experimental results show that the proposed scheme is robust against different types of attacks.

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.

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.

Several methods are exploited to watermark digital images as a safety measure for storing information, but an attacker can destroy the information by cropping a segment of the watermarked image. In recent years, numerous schemes were proposed that reduce the impact of such attacks. A new method has been proposed to confront cropping attack that is carried out using two sudoku tables. In this method, the watermark image is scattered in two sudoku table layouts with different solutions and is watermarked in the host image. Using this method, the watermark image is repeated 81 times in the host image, and to this effect the watermark image can be reconstructed using other segments when cropped by the attacker. Both sudokus used in this paper are in the classic 9×9 form and using this method, resistance to cropping attacks increases up to 98.8%.

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.

Capturing of digital images through Mobile based e-governance applications are growing day-by-day and issue related to protection of copyrights of digital images has become very critical. Protecting these high-volume geo-tagged time stamped digital images captured through android apps and ensuring that these images are suitable for social audit are key challenge for today’s application development. Digital image watermarking is a process by which secret information can be in digital images so that it is possible to guard copyrights. The paper discusses an efficient digital image watermarking system using lifting wavelet transform. The proposed algorithm aims to minimize distortion of selected watermarked image. The performance of the algorithm has been tested using available images with MATLAB and their results have been properly analyzed with existing methods. The variance value between coefficients of lifting wavelet transform (LFT) in a block with size 2 x 2 has been chosen for embedding the binary watermark and the blocks are also then shuffled randomly. The result of various experiments has demonstrated that the developed algorithm is robust against various types of attacks being applied.

Digital image watermarking is one of the largest research fields, and it plays a vital role in digital information authentication and security. Based on the study of watermarking systems, the whole process may be segregated into the processes of watermark embedding and extraction. In this paper, a review of the theoretical and experimental analysis and performance measurement of representative digital image watermarking systems in spatial and transform domains is presented. The significant characteristics of the digital image watermarking scheme are robustness, capacity, imperceptibility, the security of the hiding place, and false-positive of the watermarking algorithm. Comparison of the different watermarking techniques such as the least significant bit (LSB), singular value decomposition (SVD), the discrete wavelet transform (DWT), and the discrete cosine transform (DCT) is presented in a tabular form. A detailed discussion along with an algorithm for digital image encryption/decryption through embedding and extraction is given. A brief comparison of their relative advantages and disadvantages is also noted in this paper.KeywordsInformation hidingWatermarkingSecurityAttacksRobust