Grayscale Watermark Research Articles

Enhancing Counterfeit Detection with Multi-Features on Secure 2D Grayscale Codes

Counterfeit products have become a pervasive problem in the global marketplace, necessitating effective strategies to protect both consumers and brands. This study examines the role of cybersecurity in addressing counterfeiting issues, specifically focusing on a multi-level grayscale watermark-based authentication system. The system comprises a generator responsible for creating a secure 2D code, and an authenticator designed to extract watermark information and verify product authenticity. To authenticate the secure 2D code, we propose various features, including the analysis of the spatial domain, frequency domain, and grayscale watermark distribution. Furthermore, we emphasize the importance of selecting appropriate interpolation methods to enhance counterfeit detection. Our proposed approach demonstrates remarkable performance, achieving precision, recall, and specificities surpassing 84.8%, 83.33%, and 84.5%, respectively, across different datasets.

A Hyper-Chaotically Encrypted Robust Digital Image Watermarking Method with Large Capacity Using Compress Sensing on a Hybrid Domain.

The digital watermarking technique is a quite promising technique for both image copyright protection and secure transmission. However, many existing techniques are not as one might have expected for robustness and capacity simultaneously. In this paper, we propose a robust semi-blind image watermarking scheme with a high capacity. Firstly, we perform a discrete wavelet transformation (DWT) transformation on the carrier image. Then, the watermark images are compressed via a compressive sampling technique for saving storage space. Thirdly, a Combination of One and Two-Dimensional Chaotic Map based on the Tent and Logistic map (TL-COTDCM) is used to scramble the compressed watermark image with high security and dramatically reduce the false positive problem (FPP). Finally, a singular value decomposition (SVD) component is used to embed into the decomposed carrier image to finish the embedding process. With this scheme, eight grayscale watermark images are perfectly embedded into a carrier image, the capacity of which is eight times over that of the existing watermark techniques on average. The scheme has been tested through several common attacks on high strength, and the experiment results show the superiority of our method via the two most used evaluation indicators, normalized correlation coefficient (NCC) values and the peak signal-to-noise ratio (PSNR). Our method outperforms the state-of-the-art in the aspects of robustness, security, and capacity of digital watermarking, which exhibits great potential in multimedia application in the immediate future.

A sophisticated and provably grayscale image watermarking system using DWT-SVD domain.

Digital watermarking has attracted increasing attentions as it has been the current solution to copyright protection and content authentication in today’s digital transformation, which has become an issue to be addressed in multimedia technology. In this paper, we propose an advanced image watermarking system based on the discrete wavelet transform (DWT) in combination with the singular value decomposition (SVD). Firstly, at the sender side, DWT is applied on a grayscale cover image and then eigendecomposition is performed on original HH (high–high) components. Similar operation is done on a grayscale watermark image. Then, two unitary and one diagonal matrices are combined to form a digital watermarked image applying inverse discrete wavelet transform (iDWT). The diagonal component of original image is transmitted through secured channel. At the receiver end, the watermark image is recovered using the watermarked image and diagonal component of the original image. Finally, we compare the original and recovered watermark image and obtained perfect normalized correlation. Simulation consequences indicate that the presented scheme can satisfy the needs of visual imperceptibility and also has high security and strong robustness against many common attacks and signal processing operations. The proposed digital image watermarking system is also compared to state-of-the-art methods to confirm the reliability and supremacy.

Vowel and non-vowel frame segmentation based digital speech watermarking technique using LPA method

With the increased use of the Internet in everyday life, data transmission over the internet needs to be secure, so it necessitates the adoption of watermarking. Watermarking is the best solution for securing digital content and ensuring the integrity of the original data. It also certifies digital content and provides the best form of concealing information for permission. In many circumstances, the information is problematic as the use of digital content evolves rapidly. In this paper, we have proposed a novel speech watermarking method based on vowel and non-vowel frame segmentation using the Linear predictive analysis (LPA) method. The different vowel frame segments have been used in the LPA method to estimate the predicted values. The proposed model has used the LPA method, which allows for a more adaptive and skilful demonstration of a novel digital speech watermarking method. Afterwards, the specific locations have been chosen to embed the minimum value obtained from the grayscale watermark image. For the evaluation purpose, we have considered objective and subjective measures. The average SNR, MOS, and BER values of the proposed method are 45.68 dB, 4.55, and 0, respectively. The imperceptibility of watermarked speech and extracted watermark signals using the proposed method have approximately 48 dB, and 59 dB, respectively. The results show that the proposed speech watermarking procedure is more secure, powerful, and subtle than existing watermarking techniques because it reduces time and memory significantly.

A blind robust color image watermarking method based on discrete wavelet transform and discrete cosine transform using grayscale watermark image

AbstractWith the rapid development of internet technology, digital images are easily accessed and tampered by unauthorized users. Therefore, copyright of color images has become an important challenge in nowadays. Robust color image watermarking methods have emerged to provide copyright. However, robust watermarking methods must satisfy the requirements such as robustness, imperceptibility, capacity, and security. Therefore, researchers are focused on methods using grayscale watermark instead of the binary watermark to increase capacity. Grayscale watermark based robust color image watermarking methods are mostly semi‐blind and non‐blind. However, these methods have limited utilization areas since the original image, original watermark, or side information is required. To address these drawbacks, we propose a blind robust color image watermarking method using grayscale watermark. In the proposed watermark embedding procedure, one‐level discrete wavelet transform is performed on the Cb color component. Then, scrambled watermark pixels are hidden into coefficients of discrete cosine transform (DCT) matrices of LL subband by using dividing‐based new watermark embedding formula. In the watermark extracting procedure, watermark pixels are extracted from coefficients of DCT matrices by using dividing‐based extracting formula. The performance is demonstrated against various attacks and experimental results indicate that the presented method ensures robustness while preserving imperceptibility.

Blind, Secured and Robust Watermarking for 3-D Polygon Mesh using Vertex Curvature

In this paper a blind, imperceptible, robust and secure watermarking scheme for 3-D mesh models is presented. Here, the watermark is embedded in deeper surface vertices to minimize the perceivable distortion. Deeper surface vertices are selected on the basis of their mean curvature (lesser than zero) and converted to spherical coordinates. Out of the three spherical coordinates, radial distance represents approximate mesh and is invariant to distortionless attack. Therefore, watermark bits are embedded by modifying the distribution of radial distance to make the proposed scheme robust against such attacks. Radial distances are divided into bins and normalized to range in [0, 1]. Each bin accommodates one watermark bit. Watermark is embedded repeatedly in the 3-D mesh to resist cropping and simplification attack. To ensure higher security, a 128-bit unique watermark is generated by hashing (MD5 algorithm) the mean of histogram map obtained from a grayscale watermark image. Watermark bits are extracted from bins by comparing mean of each bin with a reference value. Since original mesh is not required at the time of extraction, the proposed scheme is blind. Through experimental results, it is demonstrate that the proposed scheme has good visual masking and higher robustness against various attacks. It shows improved performance as compared to some of the prominent schemes.

PCA-DTT 2D-DHCES based attack resilient imperceptible image watermarking

Most schemes exhibit low robustness due to LSB’s (Least Significant Bit) and MSB’s (Most Significant Bit) based information hiding in the cover image. However, most of these IW schemes have low imperceptibility as the cover image distortion reveals to the attacker due to information hiding in MSB’s. In this paper, a hybrid image watermarking scheme is proposed based on integrating Robust Principal Component Analysis (R-PCA), Discrete Tchebichef Transform (DTT), and Singular Value Decomposition (SVD). A grayscale watermark image is twisted/scrambled using a 2D Discrete Hyper-chaotic Encryption System (2D-DHCES) to boost up the robustness/heftiness and security. The original cover image is crumbled into sparse components using R-PCA and using DTT the substantial component is additionally decomposed and the watermark will be embedded in the cover image using SVD processing. In DTT, scarcer coefficients hold the utmost energy, also provide an optimum sparse depiction of the substantial image edges and features that supports proficient retrieval of the watermark image even after unadorned image distortion based channel attacks. The imperceptibility and robustness of the proposed method are corroborated against a variety of signal processing channel attacks (salt and pepper noise, multi-directional shearing, cropping, and frequency filtering, etc.). The visual and quantifiable outcomes reveal that the proposed image watermarking scheme is much effective and delivers high forbearance against several image processing and geometric attacks.

Vulnerability Attacks of SVD-Based Video Watermarking Scheme in an IoT Environment

This study reviews the superiority and limitations of the Singular Value Decomposition (SVD)-based video watermarking scheme. First applies key frame selection to the video sequence to obtain an appropriate video frame for the purpose of watermark embedding in this paper. The Fibonacci-Lucas image transformation scrambles the grayscale watermark image before the embedding process. The former scheme satisfies the imperceptibility and robustness aspects. However, it can suffer from the False-Positive-Problem (FPP) in which a counterfeit watermark image can be easily reconstructed by a malicious attacker. This study presents a new technique for overcoming the FPP of the aforementioned scheme. The proposed method embeds the principal components of the watermark image rather than the Singular Value Matrix (SVM) into the host video. As results, the proposed methods yield promising results in terms of imperceptibility as well as robustness. At the same time, it solves the FPP. A theoretical analysis of embedded watermark information is also provided in this work. The theoretical analysis meets the experimental-based results in the SVD-based video watermarking scheme.

A novel hybrid DCT and DWT based robust watermarking algorithm for color images

In this paper, a novel robust color image watermarking method based on Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) is proposed. In this method, RGB cover image is divided into red, green and blue components. DCT and DWT are applied to each color components. Grayscale watermark image is scrambled by using Arnold transform. DCT is performed to the scrambled watermark image. Transformed watermark image is then divided into equal smaller parts. DCT coefficients of each watermark parts are embedded into four DWT bands of the color components of the cover image. The robustness of the proposed color image watermarking has been demonstrated by applying various image processing operations such as rotating, resizing, filtering, jpeg compression, and noise adding to the watermarked images. Experimental results show that the proposed method is robust to the linear and nonlinear attacks and the transparency of the watermarked images has been protected.

T-SVD-Based Robust Color Image Watermarking

In order to protect the copyright of the color image, a robust color image watermarking method based on Tensor-Singular Value Decomposition (T-SVD) is proposed. In order to preserve strong correlations of the RGB three channels of the color image, the color image is considered as the third-order tensor, which is transformed by using T-SVD to obtain two orthogonal tensors and one diagonal tensor. Since the diagonal tensor includes the main energies of the color image, it can be exploited to embed watermark for robustness. Firstly, the three channels of the color image are decomposed by using discrete wavelet transform (DWT) into four subbands, respectively, and the LL subband of each channel is used to construct an approximation image. Secondly, the approximation image is divided into non-overlapping blocks with the size of 4 × 4, and the TSVD is applied in each block to compute the first, the second and the third diagonal matrices. Finally the grayscale watermark is decomposed by using Singular Value Decomposition (SVD). The principal components of the gray-scale watermark are embedded by modifying the first diagonal matrix of each block, since the first diagonal matrix is more robust than other two diagonal matrices. Experiment results show that the proposed method can resist a variety of image attacks, and is more robust than the existing watermarking methods.

Optimized watermarking technique using self-adaptive differential evolution based on redundant discrete wavelet transform and singular value decomposition

Imperceptibility, capacity, robustness and security are four basic requirements of any watermarking technique. A new blind image watermarking technique based on the redundant discrete wavelet transform (RDWT) and singular value decomposition (SVD) is presented in this paper to satisfy all of these four watermarking requirements simultaneously. The gray-scale watermark image is directly embedded into the singular values of RDWT sub-bands after multiplying by a scaling factor. The self-adaptive differential evolution (SADE) algorithm is used to optimize the scaling factor values with the aim of reaching the highest possible robustness while guaranteeing a pre-determined watermarked image quality. By the use of human visual system (HVS) characteristics, an 8-bits digital signature is inserted into the watermarked image to solve the false positive problem which is a prevalent security problem for the most SVD-based watermarking methods. The digital signature is used for verification test before initialization of the watermark extraction procedure. Also, considering the existing redundancy in the RDWT domain, the scheme attained a large amount of capacity. Experimental results demonstrate that in addition to achieving a great imperceptibility, large capacity and sufficient security, the proposed scheme obtains a satisfactory level of robustness against image processing and geometrical attacks, simultaneously.

Selective bit embedding scheme for robust blind color image watermarking

In this paper, we propose a novel robust blind color image watermarking method, namely SMLE, that allows to embed a gray-scale image as watermark into a host color image in the wavelet domain. After decomposing the gray-scale watermark to component binary images in digits ordering from least significant bit (LSB) to most significant bit (MSB), the retrieved binary bits are then embedded into wavelet blocks of two optimal color channels by using an efficient quantization technique, where the wavelet coefficient difference in each block is quantized to either two pre-defined thresholds for corresponding 0-bits and 1-bits. To optimize the watermark imperceptibility, we equally split the coefficient modified quantity on two middle-frequency sub-bands instead of only one as in existing approaches. The improvement of embedding rule increases approximately 3 dB of watermarked image quality. An adequate trade-off between robustness and imperceptibility is controlled by a factor representing the embedding strength. As for extraction process, we exploit 2D Otsu algorithm for higher accuracy of watermark detection than that of 1D Otsu. Experimental results prove the robustness of our SMLE watermarking model against common image processing operations along with its efficient retention of the imperceptibility of the watermark in the host image. Compared to state-of-the-art methods, our approach outperforms in most of robustness tests at a same high payload capacity.

Watermarking Scheme with CS Encryption for Security and Piracy of Digital Audio Signals

In this article, a watermarking scheme using Curvelet Transform with a combination of compressive sensing (CS) theory is proposed for the protection of a digital audio signal. The curvelet coefficients of the host audio signal are modified according to compressive sensing (CS) measurements of the watermarked data. The CS measurements of watermark data is generated using CS theory processes and sparse coefficients (wavelet coefficients of DCT coefficients). The proposed scheme can be employed for both audio and speech watermarking. The gray scale watermark image is inserted into the host digital audio signal when the proposed scheme is used for audio watermarking. The speech signal is inserted into the host digital audio signal when the proposed scheme is employed for speech watermarking. The experimental results show that proposed scheme performs better than the existing watermarking schemes in terms of perceptual transparency.

An SVD Based Location Specific Robust Color Image Watermarking Scheme Using RDWT and Arnold Scrambling

In recent times, effectiveness of the robust image watermarking scheme almost successfully solves the authenticity and copyright protection problem of images. Among several existing robust watermarking schemes, very few have been designed for color images. In this paper, the authors have proposed a redundant discrete wavelet transform (RDWT) and singular value decomposition based hybrid robust color image watermarking method where scrambled watermark is used for embedding purpose to provide extra security to authentic logo. At first, RGB color image is converted to YCbCr color image and then the Y component of YCbCr color space is used to insert Arnold scrambled grayscale watermark. In the next step, Y component of the YCbCr color model is decomposed into non overlapping blocks and subsequently RDWT are applied to each block. For better imperceptibility and effectiveness, in this proposed algorithm some singular values of RDWT transformed Y component blocks are modified by non overlapping decomposed and scrambled watermark blocks. Robustness of the proposed method is experimented against common geometric transformation attacks (like rotation, flip operation, cropping, scaling, shearing and deletion of lines or column operation etc.), common enhancement technique attacks (like lowpass filtering, histogram equalization, sharpening, gamma correction, noise addition etc.), jpeg compression attacks, some combinational attacks and satisfactory results are achieved. For better evaluation, proposed scheme is verified against standard benchmark software “Checkmark”.

Attack resistant watermarking technique based on fast curvelet transform and Robust Principal Component Analysis

Watermarking is a technique which embeds the copyright information/identifier to provide authenticity in robust and imperceptible manner. In this paper, a hybrid watermarking technique is proposed based on combination of Fast Curvelet Tansform (FCT), Robust Principal Component Analysis (RPCA) and Singular Value Decomposition (SVD). The gray-scale watermark logo is scrambled using Generalized Arnold Transform (GAT) to enhance the robustness and security. The original image is decomposed to low rank and sparse components using RPCA; the curvelet coefficients are obtained using FCT via Unequally-Spaced Fast Fourier Transforms (USFFT) to embed the processed watermark using SVD into the color image. In curvelet transform, fewer coefficients contain the most energy, also giving optimally sparse representation of the significant image features and edges that helps in efficient recovery of the embedded watermark even after severe image degradation. The robustness and imperceptibility of the proposed technique is verified against a variety of processing operations (noise, filtering) and geometric attacks (crop, resize, projection etc.). The quantitative and visual results reveal that the watermarking technique proposed is more efficient and provides high tolerance against different geometric and image processing attacks.

An optical color image watermarking scheme by using compressive sensing with human visual characteristics in gyrator domain

A novel optical color image watermarking scheme considering human visual characteristics is presented in gyrator transform domain. Initially, an appropriate reference image is constructed of significant blocks chosen from the grayscale host image by evaluating visual characteristics such as visual entropy and edge entropy. Three components of the color watermark image are compressed based on compressive sensing, and the corresponding results are combined to form the grayscale watermark. Then, the frequency coefficients of the watermark image are fused into the frequency data of the gyrator-transformed reference image. The fused result is inversely transformed and partitioned, and eventually the watermarked image is obtained by mapping the resultant blocks into their original positions. The scheme can reconstruct the watermark with high perceptual quality and has the enhanced security due to high sensitivity of the secret keys. Importantly, the scheme can be implemented easily under the framework of double random phase encoding with the 4f optical system. To the best of our knowledge, it is the first report on embedding the color watermark into the grayscale host image which will be out of attacker's expectation. Simulation results are given to verify the feasibility and its superior performance in terms of noise and occlusion robustness.

A RDWT and Block-SVD based Dual Watermarking Scheme for Digital Images

In the modern era, digital image watermarking is a successful method to protect the multimedia digital data for example copyright protection, content verification, rightful ownership identification, tamper detection etc. In this paper for improving the robustness and security, a Dual watermarking approach using Redundant Discrete Wavelet Transform (RDWT), block based singular value decomposition (SVD) and Arnold transform is presented. There are two gray scale watermarks, one is Prime watermark and other is Arnold scrambled Second watermark. Second watermark is embedded into the RDWT transformed Prime watermark in all sub bands to get the processed watermark image. After that transformed gray scale cover image is partitioned into non-overlapping blocks for embedding the processed watermark image by modifying the SVD coefficients of each block to obtain the resultant watermarked image. Now a reverse algorithm is developed to takeout the Prime and Second watermark from noisy image. Analysis and experimental outcomes show that the presented method is more robust against numerous image processing attacks and perform better as compared to previously introduced schemes related to presented work.

Multipurpose image watermarking in the domain of DWT based on SVD and ABC

A multipurpose image watermarking scheme is proposed in the present work in order to provide tamper localization, self-recovery and ownership verification of the host image. For robust watermarking, gray scale watermark is utilized to provide generalization and wide applicability to proposed scheme. The host is first transformed into the wavelet domain using DWT (Discrete Wavelet Transform) and then singular values of transformed host are modified in accordance with the principal components of watermark. This insertion make the scheme free from false positive error as well as it provides a decent capacity too. After the insertion of robust watermark, the last two LSB (Least Significant Bit) of host are modified in such a way that it contains the scrambled and deterministic average representation of host itself along with the SVD (Singular Value Decomposition) based tamper localization information. The LSB insertion is used to locate the tampered region as well as to provide the self-recovery feature to the scheme. The robust insertion is also optimized with the help of ABC (Artificial Bee colony) in such a way that maximum robustness can be assured corresponding to user specific threshold of imperceptibility.

An Adaptive Gray Scale Watermarking Method in Wavelet Domain

In the past a few years, many watermarking approaches have been proposed for solving the copyright protection problems. This paper presents a new gray scale watermarking method in wavelet domain based on the compression of the watermark and the pretreatment of the original image. Through the compression of watermark, it can greatly reduce the embedding capacity of the watermark, which can embed more watermark bits in the host image. Through the preprocessing of the original image based on human visual system’s characteristic, it can ensure the imperceptibility. The use of threshold T can adaptively determine the quantity of embedded blocks, and control the capacity of embedded secret information. The experimental results show that our method has an excellent transparency and robustness.

An Adaptive Grayscale Watermarking Method in Spatial Domain

An Adaptive Grayscale Watermarking Method in Spatial Domain