Watermark Embedding Process Research Articles

Binocular visual characteristics based fragile watermarking scheme for tamper detection in stereoscopic images

In the past decade, various fragile digital watermarking techniques have been proposed for monoscopic image authentication and temper detection. In this paper, a novel binocular visual characteristics based pixel-wise fragile watermarking scheme for stereoscopic image authentication and tamper detection is proposed. The scheme consists of two processes: embedding of the stereoscopic image authentication message and tamper detection. In the watermark embedding process, the binocular just noticeable difference (BJND) model is used for guiding watermark embedding, which is convenient for achieving a balanced relationship between watermarking capacity and visual transparency. In the tamper detection process, a probability theory and an algorithm of binocular disparity are employed to improve previously obtained detection results and to enhance authentication accuracy. Moreover, to improve the security of the proposed scheme, MD5 hash function and chaotic map are used. Experimental results reveal that the proposed scheme is not only secure, but also achieves superior tamper detection for different attacks.

A spiral based image watermarking scheme using Karhunen–Loeve and discrete hartley transforms

The main objective of developing the image watermarking technique is satisfying the robustness and the imperceptibility of multimedia protection. To achieve this objective, a novel hybrid image watermarking scheme based on Karhunen Loeve transform (KLT) and discrete hartley transform (DHT) and is proposed. In the proposed scheme (KL---DHT based watermarking scheme), the original image is divided into blocks using spiral scan, then the DHT is calculated for each block, after that, the KLT is applied for each DHT block. The watermark embedding process is carried out during the KLT transformation process. In the watermark extracting process, the watermarked image is distorted using several image attacks such as JPEG image compression, image rotation, image resizing, adding noise (Gaussian, impulsive or speckle) or image contrast adjustment using adaptive histogram equalization. Furthermore, the proposed scheme is carried out using block by block image scan and the achieved results are compared with those obtained from other watermarking schemes such as discrete cosine transform/singular value decomposition (DCT---SVD) based watermarking scheme, discrete wavelet transform/SVD (DWT---SVD) based watermarking scheme and SVD watermarking in the homomorphic domain watermarking scheme. The achieved results proved that, the superiority of the KL---DHT based watermarking scheme with spiral scan compared to other watermarking schemes in the presence of different image attacks.

Watermarking Digital Artworks

paper presents a digital watermarking scheme based on a new application of DWT and SVD for color artworks protection. This scheme uses the major features of the two chrominance components where the watermark bits are embedded only into one chrominance component according to the color prevalence rate. In watermark embedding process, more modifications can be done upon the selected chrominance component, while more readable information is needed during the watermark extraction process. Simulation results demonstrate that the proposed scheme yields a high level of robustness against various image processing operations without sacrificing the visual quality of watermarked artwork image.

Steganography of Digital Watermark Based on Artificial Neural Networks in Image Communication and Intellectual Property Protection

In this paper, a novel steganography of digital watermark scheme which contains digital watermark embedding and extraction processes is proposed. The proposed scheme is based on an iterative process of Arnold scrambling transform which is controlled by secret key shared by copyright owner and authorized users, and the extension of morphological component analysis theory which utilizes morphological diversity as the kernel role in blind source separation. This scheme overcomes the problem of too narrow hidden data bandwidth in traditional LSB replacement or LSB matching schemes. Compared with classic JPEG steganography schemes, the proposed scheme has much higher embedding capacity and broader applicability scope. Images acquired in experiments and the analysis of experimental results both prove the effectiveness of proposed scheme. Objective quantitative results of the peak signal to noise ratio, structural similarity, and normalized correlation indices confirm its brilliant steganography capability as well as its fine robustness to different noise attacks through communication channel.

FPGA prototyping of video watermarking for ownership verification based on H.264/AVC

Digital video watermarking has drawn the attention towards authentication and proof of ownership. Uncompressed domain watermarking has flourished over the years and related algorithms have been implemented on the software platform. Software watermarking algorithms work offline where videos are captured through device and embedding algorithms run on a PC that is used to embed the watermark in the original video content. It doesn't suffice real time requirements because of the delay that takes place between capturing and embedding the watermark. This delay involvement is more prone to attacks. Thus, it is essential to develop the system where the watermark gets embedded at the same time when video is being captured. In this paper, an efficient watermark embedding process has been portrayed which is suited to H.264/AVC standard. The proposed algorithm introduces the concept of scene change detection based on Integer Discrete Cosine Transform (Integer-DCT) using scene change detection. The different frames of a scene are embedded with different bit planes of the same watermark in order to improve the performance against temporal attacks. The algorithm is validated on the MATLAB platform and is prototyped on FPGA to show its feasibility for real-time application.

A Novel Watermark Embedding Scheme using Compressive Sensing in Wavelet Domain

Most existing research achievements of digital watermarking techniques are in transform domain. In compari- son with spatial domain, its advantages are larger data volume, higher security and stronger robustness. But its limitations are also obvious: complex computing requirement, weak in resisting attack and anti-extraction. In this paper, a novel blind digital watermarking algorithm is proposed, which performs digital watermark embedding process in Compressive Sens- ing (CS) domain based on the characteristics of CS and Human Visual System (HVS). The sub-blocks with larger capac- ity are selected to embed the scrambled digital watermark, considering the non-uniformity of blocks. Besides that, suitable quantization steps are chose adaptively by using quantization method. Experimental results show that the algorithm ob- tains robust and invisible embedded watermark with larger capacity of data. At the same time, the ability of defending against attack or extraction of embedded watermark is greatly improved. Most important feature in our algorithm is that the watermark can be extracted without any reference to the original image. As a result, the cost of storing carrier data can be saved remarkably.

IJARCCE - Computer and Communication Engineering

The rapid growth of network distributions of images and video, there is a need for copyright protection against piracy. For this purpose we are using video watermarking. Different digital watermarking schemes have been proposed to address this issue of ownership identification. Digital watermarking is a process by which user specified signal (Watermark) is hidden or embedded into another signal (Video Signal) by the watermark embedding process. Afterwards the recovery of the watermark is achieved with the help of the watermark extraction process. The video watermark is robust against the attack of frame dropping, averaging and statistical analysis. It leads to broad curiosity in multimedia security and multimedia copyright protection. The most important issue in video watermarking is the invisibility of the watermark and the resilience of watermarking to attacks. Watermarking techniques are classified into three categories. They are Spatial Domain Method (SDM), Transform Domain Method (TDM) and Compressed Domain Method (CDM). Here explained about to transform domain method. This method used the discrete cosine transform (DCT), Discrete Fourier Transform (DFT) and Discrete Wavelet Transform (DWT) for watermark embedding.DWT are more popularity due to their spatial localization, frequency spread etc.. But DCT watermarking was to human perception model to modify low coefficients of DCT blocks. It has a larger embedding capacity and robustness. This technique provides better results with high accuracy.

Digital Image Watermarking using Fibonacci Transform in YIQ Color Space

Digital watermarking is a technique for inserting ownership information to the digital data to prove the authenticity. A digital watermarking is perceptually invisible to prevent obstruction of the original image. It is also used for tamper proofing, broadcast monitoring, covert communication etc. In this paper, a wavelet-based watermarking approach for hiding watermark image in color host images is proposed. The host image is converted into YIQ color space and then Y channel decomposed into wavelet coefficients. This proposed methodology overcomes the drawback of the existing approaches and enhances the security by applying Arnold transform and Fibonacci transform for embedding the resultant pattern in the host image. The watermark embedding process does not degrade the visual quality of the image.

Adaptive reversible data hiding based on a local smoothness estimator

A novel reversible watermarking (RW) scheme based on a local smoothness estimator and multi-step embedding strategy is proposed in this paper. All the pixels are divided into four equal parts. Correspondingly, the watermark embedding process is separated into four independent steps. Thus each step is performed to embed watermark information into its corresponding image part. In each step, for each to-be-embedded pixel, a local smoothness estimator defined as the variance of its total neighbors is presented to estimate its local smoothness. An obvious advantage of introducing this estimator is that it can determine those pixels in smooth regions accurately. In fact, accurate determination means the decrease in embedding distortion. At the low embedding rate (ER), modifications induced by difference expansion (DE) are done only to those pixels located in smooth regions. Hence, the proposed method can obtain high embedding capacity while maintaining good visual quality. With ER gradually increased, adaptive embedding is employed. In adaptive embedding, for one to-be-embedded pixel, 1 or 2 bits are adaptively embedded according to the strength of relationship among all the pixels surrounding it. The experimental results demonstrate that the proposed method is effective.

Hiding patients confidential datainthe ECG signal viaa transform-domain quantization scheme.

Watermarking is the most widely used technology in the field of copyright and biological information protection. In this paper, we use quantization based digital watermark encryption technology on the Electrocardiogram (ECG) to protect patient rights and information. Three transform domains, DWT, DCT, and DFT are adopted to implement the quantization based watermarking technique. Although the watermark embedding process is not invertible, the change of the PQRST complexes and amplitude of the ECG signal is very small and so the watermarked data can meet the requirements of physiological diagnostics. In addition, the hidden information can be extracted without knowledge of the original ECG data. In other words, the proposed watermarking scheme is blind. Experimental results verify the efficiency of the proposed scheme.

3D image copyright protection based on cellular automata transform and direct smart pixel mapping

We propose a three-dimensional (3D) watermarking system with the direct smart pixel mapping algorithm to improve the resolution of the reconstructed 3D watermark plane images. The depth-converted elemental image array (EIA) is obtained through the computational pixel mapping method. In the watermark embedding process, the depth-converted EIA is first scrambled by using the Arnold transform, which is then embedded in the middle frequency of the cellular automata (CA) transform. Compared with conventional computational integral imaging reconstruction (CIIR) methods, this proposed scheme gives us a higher resolution of the reconstructed 3D plane images by using the quality-enhanced depth-converted EIA. The proposed method, which can obtain many transform planes for embedding watermark data, uses CA transforms with various gateway values. To prove the effectiveness of the proposed method, we present the results of our preliminary experiments.

A Semi-fragile Image Watermarking Scheme Exploiting BTC Quantization Data

This paper proposes a novel blind image watermarking scheme exploiting Block Truncation Coding (BTC). Most of existing BTC-based watermarking or data hiding methods embed information in BTC compressed images by modifying the BTC encoding stage or BTC-compressed data, resulting in watermarked images with bad quality. Other than existing BTC-based watermarking schemes, our scheme does not really perform the BTC compression on images during the embedding process but uses the parity of BTC quantization data to guide the watermark embedding and extraction processes. In our scheme, we use a binary image as the original watermark. During the embedding process, the original cover image is first partitioned into non-overlapping 4×4 blocks. Then, BTC is performed on each block to obtain its BTC quantized high mean and low mean. According to the parity of high mean and the parity of low mean, two watermark bits are embedded in each block by modifying the pixel values in the block to make sure that the parity of high mean and the parity of low mean in the modified block are equal to the two watermark bits. During the extraction process, BTC is first performed on each block to obtain its high mean and low mean. By checking the parity of high mean and the parity of low mean, we can extract the two watermark bits in each block. The experimental results show that the proposed watermarking method is fragile to most image processing operations and various kinds of attacks while preserving the invisibility very well, thus the proposed scheme can be used for image authentication.

Stable watermarking technique based on XNOR operation and scale relationship

Digital watermark technique is often used to solve these problems and protect the copyright of multimedia transferred over the Internet. Most watermark methods use pixel values or coefficients as the judgment condition to embed or extract a watermark image. The variation of these values may lead to the inaccurate condition such that an incorrect judgment has been laid out. To avoid this problem, we design a stable judgment mechanism, in which the outcome will not be seriously influenced by the variation. The principle of judgment depends on the scale relationship of two pixels. From the observation of common signal processing operations, we can find that the pixel value of processed image usually keeps stable unless an image has been manipulated by cropping attack or halftone transformation. In the watermark embedding process, we use the XNOR operation to record the outcome to form a secret key instead of modifying pixel values. This can greatly help reduce the modification strength from image processing operations. Experiment results show that the proposed method can resist various attacks and keep the image quality friendly.

A Visual Complexity-sensitive DWT Ordering Scheme for Hiding Data in Images

A scheme is proposed to hide data in images based on a prioritized ordering of the content of the host (or cover) image. A watermark embedding process uses the watermark strength to determine the ordering of the 16 regions resulting from the second level Discrete Wavelet Transform (DWT) decomposed content of the host image. To determine the best ordering for hiding the data, various types of image of varying content and, hence, visual complexity were considered, analyzed and ranked in terms of their ability to withstand changes that do not imperil the visual quality (PSNR) of their watermarked versions depending on which an N×N-sized watermark stream is hidden in the 8 highest ranked sub-bands of the host image. From this perspective, an ordering for images classified as simple, normal and complex images was used to determine a generalized ordering of the DWT decomposed sub-bands of the image. The generalized ordering presented here ascertains that the content of the image and its visual complexity had little effect on an earlier proposed prioritized ordering of the DWT Sub-bands. To validate the veracity of the ordering scheme, 1000 images from the Corel 1000A database, their visual complexity and features were taken into account. The results confirmed that high embedding capacity, appreciable visual quality of watermarked images and complete recovery hidden data are realizable based on the ordering scheme proposed in this study.

Robust logo watermarking using biometrics inspired key generation

In this paper, a novel logo watermarking technique with key concept is proposed using fractional wavelet packet transform (FrWPT), non-linear chaotic map and singular value decomposition (SVD). The core idea is to use biometrically generated keys in the embedding process of gray-scale watermark. Therefore, this paper first proposes a method for generating keys from biometrics efficiently. Then the host image is first randomized with the help of non-linear chaotic map followed by the embedding in the FrWPT domain by modifying the singular values of the randomized image. Further, in order to enhance the security, an authentication key is formed to authenticate the watermarked image. Finally, a reliable extraction process is proposed to extracted watermark from the possibly attacked authenticate watermarked image. The security, attack and comparative analysis confirm high security, efficiency and robustness of the proposed watermarking technique. Further, an efficient solution is also proposed to deal with the ambiguous situations created by SVD in watermarking.

A New Robust Blind Watermarking Scheme Based on Steerable pyramid and DCT using Pearson product moment correlation

In this paper, we present a new, robust digital watermarking scheme for ownership protection. The scheme is based on Steerable Pyramid (SP) and discrete cosine transform (DCT) using Pearson product moment correlation. During the process of watermark embedding, SP is performed on original host image, and corresponding oriented sub-band is selected to carry the watermark. DCT is applied to each block of size 8x8 of the selected sub-band. Two independent streams representing the watermark are embedded in low and mid-frequency of DCT components. Watermark detection is based on comparison result between Pearson product moment correlations of the two independent streams with each watermarked block. The experimental results demonstrate good visual imperceptibility and resiliency of the proposed scheme against an intentional and un-intentional variety of attacks.

Efficient video watermarking with SWT and empirical PCA based decoding

Digital content piracy is one of the major crimes in the present world. Protection of digital content like music, video and images has become a major problem. Watermarking is one of the methods to protect digital content against unauthorized copying. In watermarking procedure, generally, watermark is embedded before it is going to be distributed over different communication channels. This paper presents a novel technique for embedding a image/data into video frames. Video Watermarking is a process by which user specified data is hidden or embedded into another signal (Video Signal) by the watermark embedding process. Afterwards the recovery of the watermark is achieved with the help of the watermark extraction process. The proposed scheme is an imperceptible and a robust hybrid video watermarking scheme. PCA is applied to each block of the any bands which result from Stationary Wavelet transform of every video frame. The watermark is embedded into the first principal components of the any blocks in different ways. Combining the two transforms improved the performance of the watermark algorithm. The scheme is tested by applying various attacks. Experimental results show no visible difference between the watermarked frames and the original frames. In our paper, to embed the watermark, stationary wavelet transform (SWT) is used in combination with principal component analysis (PCA) in order to increase the robustness against many attacks, to increase the amount of payload and also the processing speed. Index Terms: Video Watermarking, Stationary Wavelet Transform, Principal Component Analysis.

DCT Coefficients Modelling for Image Watermarking

It is important to select the best well-modelled coefficients of discrete cosine transform (DCT ) to satisfy the requirements of watermarking algorithm. In this paper, we proved that the low ac DCT coefficients are well modelled by using the generalized gamma distribution. A new estimator based on moment method was proposed to estimate their parameters, and the goodness-of-fit (χ2)is used to prove its effectiveness. The modelled coefficients were chosen to perform the watermark embedding process. To increase the security of our scheme, the chaotic maps have been used. Model of the probability edensity functions for the DCT watermarked images is derived, and the detector is developed based on the maximum likelihood. Simulation results proved that the proposed method has better imperceptibility, highly sensitive to the key and robust against JPEG attack when the moment method is used. With our method ewe can still detect the watermark for JPEG compression when the compression ratio is over 28.5 for all attacked watermarked images.

Robust and blind watermarking scheme for three dimensional anaglyph images

In this paper, a robust and blind watermarking scheme for three dimensional (3-D) anaglyph images is proposed. Since the computational cost of Red–Green–Blue (RGB) processing is quite high, we have used 3-D Discrete Wavelet Transform (3-D DWT) to decompose the image and process it directly. The watermark to be embedded is computed from the image and also the process involves watermark strength factor which scales the quality of the watermark. Jacket matrix is used due to its simplicity in the watermark embedding and extraction processes. Experimental results show that the proposed scheme is highly imperceptible and robust against various image processing and signal processing attacks. Comparisons with the state-of-the-art demonstrate the effectiveness of our scheme.

Perceptual watermarking using a new Just-Noticeable-Difference model

In this paper, a new watermarking scheme based on Human Visual System (HVS) modeling is proposed. The approach consists in building computational models which take into account the most common properties of the HVS that can be exploited for watermarking. Two schemes for embedding and controlling the transparency of the watermark are presented, namely the implicit and the explicit schemes. Both schemes are designed in the framework of the pyramidal decomposition which has been shown to be a powerful tool for analyzing image through a multi-scale representation. For the first approach, a multi-scale visibility map is used to optimize the watermark embedding process. The second approach makes use of HVS properties in an explicit and more sophisticated manner that consists in tuning the watermark strength just beneath the visual detection threshold. A new JND (Just-Noticeable-Difference) model for determining this threshold is then proposed and evaluated. The obtained results provide a strong support for this new JND model.