Frequency Domain Watermarking Research Articles

Robust medical image watermarking in frequency domain

Protecting patient information in medical image watermarking poses a significant challenge, especially when traditional methods like the Arnold transform prove inadequate in ensuring security. This paper introduces a novel approach within the Discrete Wavelet Transform (DWT) domain to address this issue effectively. By employing the Advanced Encryption Standard (AES), the security and robustness of the system are greatly enhanced through the encryption of both the medical image and patient data. The encrypted medical image undergoes a 2-level DWT process, allowing the concealment of encrypted patient information while maintaining its invisibility. This proposed scheme surpasses others in experimental evaluations, as evidenced by metrics such as PSNR and NC, solidifying its position as a more secure choice for medical image watermarking. The results validate the scheme’s robustness and imperceptibility.

An Overview of Robust Video Watermarking Techniques

Copyright hacking and piracy have increased as the Internet has grown in popularity and access to multimedia material has increased. Security, property protection, and authentication have all been achieved via watermarking techniques. This paper presents a summary of some recent efforts on video watermarking techniques, with an emphasis on studies from 2018 to 2022, as well as the various approaches, achievements, and attacks utilized as testing measures against these watermarking systems. According to the findings of this study, frequency-domain watermarking techniques are more popular and reliable than spatial domain watermarking approaches. Hybrid DCT and DWT are the two most used techniques and achieve good results in the field of video watermarking, and the system is more robust against attacks. PSNR was taken into consideration as a comparison metric in various recent articles in terms of robustness in the video watermarking field.

Triple byte nonlinear component of block cipher and its application in frequency domain watermarking

Triple byte nonlinear component of block cipher and its application in frequency domain watermarking

Robust Watermarking Scheme for Vector Geographic Data Based on the Ratio Invariance of DWT–CSVD Coefficients

Traditional frequency-domain watermarking algorithms for vector geographic data suffer from disadvantages such as the random watermark embedding position, unpredictable embedding strength, and difficulty in resisting multiple attacks at the same time. To address these problems, we propose a novel watermarking algorithm based on the geometric invariance of the ratios of discrete wavelet transform (DWT) and complex singular value decomposition (CSVD) coefficients, which embeds the watermark information in a new embedding domain. The proposed scheme first extracts feature points from the original vector geographic data using the Douglas–Peucker algorithm, and then constructs a complex sequence based on the feature points set. The two-level DWT is then performed on the complex sequence to obtain the low frequency coefficients (L2) and high frequency coefficients (H2). On this premise, the CSVD algorithm is utilized to calculate the singular values of L2 and H2, and the ratio of the singular values of L2 and H2 is acquired as the watermark embedding domain. During the watermark embedding process, a new watermark sequence is created by the fusion of the original watermark index value and bits value to improve the recognition of the watermark information, and the decimal part at different positions of the ratio is altered by the new watermark sequence to control the watermark embedding strength. The experimental results show that the proposed watermarking algorithm is not only robust to common attacks such as geometric, cropping, simplification, and coordinate point editing, but also can extract watermark images with a high probability under random multiple attacks.

Robust, Secure and Semi-Blind Watermarking Technique Using Flexible Scaling Factor in Block-Based Wavelet Algorithm

Multimedia security has received much attention recently because of the rapid transmission of elements such as text, images, audio, video, software, animation and games. Security is becoming especially critical for content owners concerned about the illegal usage of their original products. Encryption and watermarking are two methodologies for digital applications. Spatial domain and frequency domain watermarking algorithms give very promising results in embedding binary images into the cover images. This paper proposed a new method of semi-blind watermarking technique. The digital images are divided into 4 × 4 blocks and converted into discrete Wavelet transformations (DWTs). The binary image is embedded into each block using the flexible scaling factor method. Experimental results show that the proposed method has higher peak signal to noise ratio (PSNR) and similarity ratio (SR) values compared to the standard Wavelet transformation and block-based Wavelet algorithms. The results prove that the proposed hybrid algorithm is more effective, robust, secure and resistant than DWT and block-based DWT algorithms.

Design a Hybrid FPGA Architecture for Visible Digital Image Watermarking in Spatial and Frequency Domain

Hybrid field programmable gate array (FPGA) implementation is proposed to improve the performance of visible image watermarking systems. The visible watermarking process is implemented as pixel by pixel operation under a spatial domain or vector operation in the frequency domain. The proposed approach is mainly designed for watermarking the images taken from digital cameras of various sizes. The padding technique is used for unequal sizes of the watermark image and original host image. The architecture data path consists of eight and six stages of pipeline capable of watermarking on the pixel-based operation and vector-based operation, respectively. The dual image watermarking architecture data path consists of a 13-stage pipeline. Pipeline and parallelism mechanisms are used to improve throughput. To improve the performance in discrete cosine transform operations at the frequency domain, the shift-add technique replaces the conventional multipliers. The clock gating technique is employed to reduce the power by preventing unnecessary switching in a path. Hardware implementation of the algorithm is tested in Intel Cyclone FPGA with the device of EP4CGX22CF19C6, with which the throughput achieved is 1.27[Formula: see text]Gbits/s with a total area utilization of 35[Formula: see text]digital signal processing (DSP) blocks, 378 look-up tables (LUTs) and 486 registers.

Color image watermarking using spatio-chromatic complex Hadamard transform in sequency domain

PurposeWatermarking technique is one of the significant methods in which carrier signal hides digital information in the form of watermark to prevent the authenticity of the stakeholders by manipulating different coefficients as watermark in time and frequency domain to sustain trade-off in performance parameters. One challenging component among others is to maintain the robustness, to limit perceptibility with embedding information. Transform domain is more popular to achieve the required results in color image watermarking. Variants of complex Hadamard transform (CHT) have been applied for gray image watermarking, and it has been proved that it has better performance than other orthogonal transforms. This paper is aimed at analyzing the performance of spatio-chromatic complex Hadamard transform (Sp-CHT) that is proposed as an application of color image watermarking in sequency domain (SD).Design/methodology/approachIn this paper, color image watermarking technique is designed and implemented in SD using spatio-chromatic – conjugate symmetric sequency – ordered CHT. The color of a pixel is represented as complex number a*+jb*, where a* and b* are chromatic components of International Commission on Illumination (CIE) La*b* color space. The embedded watermark is almost transparent to human eye although robust against common signal processing attacks.FindingsBased on the results, bit error rate (BER) and peak signal to noise ratio are measured and discussed in comparison of CIE La*b* and hue, saturation and value color model with spatio-chromatic discrete Fourier transform (Sp-DFT), and results are also analyzed with other discrete orthogonal transforms. It is observed from BER that Sp-CHT has 8%–12% better performance than Sp-DFT. Structural similarity index has been measured at different watermark strength and it is observed that presented transform performs better than other transforms.Originality/valueThis work presents the details and comparative analysis of two orthogonal transforms as color image watermarking application using MATLAB software. A finding from this study demonstrates that the Complex Hadamard transform is the competent candidate that can be replaced with DFT in many signal processing applications.

Digital Watermarking For Medical Images Using Dwt And Svd Technique

In the modern world with developing technologies, all the information are collected and stored digitally. In medical field also the diagnostic information are recorded digitally and transmitted. While transferring the information digitally, security and authenticity is the main aspect to be concentrated. Watermarking is the technology which ensures the authenticity and security of the medical images, information about patient and diagnostic details. In this paper, hybrid watermarking technique by the combination of Discrete Wavelet Transform and Singular Value Decomposition is implemented, because of its high security and efficiency as compared with other frequency domain watermarking. The images have been tested against attacks like salt and pepper noise, Gaussian noise, and filtering attack. Efficiency and performance of this hybrid technique are evaluated based on PSNR, SSIM and NC. From the simulation results, PSNR is above 37 dB, which ensures better imperceptibility and shows better robustness with NC values near to 1 against image attacks during transmission.

A Blind Watermarking Algorithm Based on Wavelet Transform for 3D Model

In order to protect the visual effect of 3D model, watermarking algorithm should have good invisibility, thus a novel frequency-domain watermarking method is proposed in this paper. Robust regions of 3D model are selected as the watermarking regions in this algorithm, and watermarking regions are transformed into two-dimensional images depending on vertices distribution. Then the two-dimensional images are transformed into wavelet transform images by using wavelet transform algorithm and the watermark is embedded in low frequency coefficients of wavelet transform images. The experimental results show that the watermarking algorithm in this paper has high invisibility, and can resist common attacks such as noise, rotation, cropping and scaling.

A comparison between the performance of DWT and LWT in image watermarking

Image watermarking algorithms can be implemented using time domain or frequency domain-based algorithms. Frequency domain watermarking produces watermarks with higher robustness; hence, many attempts have been proposed in literature using different transformations as DCT, SVD, and DWT. DWT was widely used for many reasons as its spatio-temporal feature, in which the alteration of certain portion will affect only the affected portion. In this paper an experimental comparison between the traditional DWT and the second generation of wavelet which is LWT is initiated. The experimental tests evaluated the performance of both transforms in terms of image quality and watermark robustness.

Topology-Preserving and Geometric Feature-Correction Watermarking of Vector Maps

Digital watermarking is an effective method of vector map copyright protection. However, the topology and geometric features are potentially influenced by the disturbances of vertices caused by watermark embedding, thus reducing the availability of watermarked vector maps. In this research, we propose a post-correction method for two-dimensional vector map watermarking, by which the topology and geometric features of the input data can be preserved, while using only conventional watermarking techniques. In the proposed method, the Maximum Perturbation Regions (MPR) of vertices and direction angle constraints methods of adjacent lines are adopted to undergo multi-azimuth checks of watermarked vertices, which may cause changes of the geometric features and topology. After that, the coordinate adjustment method which is based on the homonymous vertices topology association and the MPR are combined for topology and geometric feature correction. For watermark embedding, two classic frequency domain watermarking techniques, Discrete Fourier Transformation (DFT) and Discrete Wavelet Transformation (DWT), phase based and low-frequency coefficient based respectively, are also adopted. The scheme was conducted on a building vector map and a road vector map. The experimental results show that the proposed method can ensure the topology consistency and geometric feature similarity of vector maps before and after embedding watermarks. Moreover, this method has little interference with the maps, which improves the usability of the watermarked vector map.

Analysis of frequency domain watermarking techniques in presence of geometric and simple attacks

Protection of manuscript accessible online is always an apprehension for researchers. Many ideas had come up for copyright protection and authentication of such documents. One of the admired keys to provide safety to the owner’s data is digital watermarking. It is the process of hiding the secret message (text, audio, image, logo, signature) into the document for providing authentication. A watermarking mechanism is said to be effectual if it offers high imperceptibility, robustness against attacks, security and last but not the least has the high correlation value of extracted watermark with the original one. Numerous survey papers are available in literature taking only a few techniques or parameters into account, but this paper takes almost all frequency domain (standalone and hybrid) methods in absence and presence of geometric and simple attacks and does an exhaustive analysis on the same. MATLAB software is used for implementation. Results illustrate the superlative technique under the influence of simple attacks is DWT-FFT, and under geometric attacks DWT-SVD is preeminent.

Invisible Semi-Fragile Watermarking and Steganography of Digital Videos for Content Authentication and Data Hiding

In the current digital age, the piracy of digital media content has become rampant. Illegal distribution of movies and video clips on a global scale causes a significant loss to the media industry. To prevent such theft and distribution of content, we use a watermarking technique for videos where copyright information is hidden inside the original video in the form of a watermark video. Using a video as the watermark facilitates the user in hiding a large amount of information. The watermarking scheme used in this paper is semi-fragile, such that tampering of videos can be detected with relative ease. To improve the robustness of the watermark, we embed the watermark in frequency domain, where we use DWT+DCT+SVD to embed the watermark. The original video and watermark video are transformed by using the DWT and DCT sequentially, then the singular values of the watermark with some embedding strength are added to the singular values of the original video thus obtaining a watermarked video. Some detection tools which are available today cannot detect the watermark video inside the original video. This method equalizes the frames of the watermark and original video to reduce time consumed as well as complexity. The effects of various attacks on the watermarked video have been analyzed using the calculated PSNR values.

A High-Capacity Reversible Watermarking Scheme Based on Shape Decomposition for Medical Images

We present a high-capacity reversible, fragile, and blind watermarking scheme for medical images in this paper. A bottom-up saliency detection algorithm is applied to automatically locate the multiple arbitrarily-shaped regions of interest (ROIs). The iterative square-production algorithm is developed to generate different sizes of squares for shape decomposition on the regions of noninterest (RONIs). This scheme of combining the frequency-domain watermarking and arbitrarily-shaped ROI methods can significantly increase the watermarking capacity, whereas the embedded image fidelity is preserved. Extensive experiments were carried out on the OASIS medical image dataset, which consists of a cross-sectional collection of 416 subjects, aged from 18 to 96 years old. The results show that the proposed scheme outperforms six existing state-of-the-art schemes in terms of watermarking capacity and embedded image fidelity.

SBPG: Secure Better Portable Graphics for Trustworthy Media Communications in the IoT

Smart Healthcare is envisioned as the combination of traditional healthcare augmented by smart bio-sensors, wearable devices, and a plethora of on-body sensors that communicate with smart hospitals, smart emergency response systems, and ambulances, through advanced information and communication technologies. The vision of smart healthcare as part of a smart city relies on the framework of the Internet of Things (IoT) as the underlying core technology that enables the design and operation of a city, whereby smart technology, energy grids, transportation, buildings, communication, and information technology, are all interconnected. This paper addresses some of the challenges faced in the IoT infrastructure, specifically secure communication and user authentication in the context of automated analysis of biomedical images and communication of the analysis results and related metadata in a smart healthcare framework. A hardware architecture for a secure digital camera integrated with the secure better portable graphics (SBPG) compression algorithm, suitable for applications in the IoT, is proposed in this paper. The focus of this paper is on patient data protection and authentication. The proposed SBPG architecture offers two layers of protection, concurrent encryption and watermarking, which address all issues related to security, privacy, and digital rights management. The experimental results demonstrate that the new compression technique BPG outperforms JPEG in terms of compression quality and compressed file size while providing increased image quality. High performance requirements of BPG have been met by employing two techniques: 1) insertion of an encrypted signature in the center portion of the image and 2) frequency-domain watermarking using blockwise DCT of size $8\times 8$ pixels. These approaches optimize the proposed architecture by decreasing computational complexity while maintaining strong protection, with concomitant increase of the speed of the watermarking and compression processes. A Simulink® prototype for the proposed architecture has been built and tested. To the best of our knowledge, the hardware architecture for BPG compression with built-in image authentication capability for integration with a secure digital camera is the first one ever proposed .

A new technique of frequency domain watermarking based on a local ring

This paper presents a new and comparatively secure watermarking technique, in the frequency domain. Our scheme deploys a local ring-based substitution box (S-box). The algebraic algorithm used to synthesize S-box basically exploits one–one correspondence between the multiplicative group of units of the local ring $${\mathbb{Z}}_{512}$$ and the Galois field $$\varvec{F}_{256}$$ . This S-box has high confusion creating capability due to the structural properties of the local ring and fulfills the necessary requirements to be reliably used in multimedia applications. We use this S-box in a watermarking scheme to make our technique more confusing and secure to provide more support in copyrights protection strategies. The proposed non-blind digital watermarking technique deals with the application of discrete cosine transform (DCT) in the frequency domain which is comparatively more robust than spatial domain techniques. In the proposed scheme, first the watermark image is substituted through the S-box, and the scrambled watermark is then embedded in the DCT-transformed host image.‘ To measure the strength of the proposed technique, simulation results and statistical analyses are made. Most significant analyses techniques including measures of homogeneity, contrast, energy, entropy, correlation, mean squared error and peak signal to noise ratio are applied which show coherent results. To determine the robustness of our is effectively strong.

A Variance based Approach (VBA) Digital Watermarking in Frequency Domain and Comparative Analysis using Walsh and Hadamard transform

A Variance based Approach (VBA) Digital Watermarking in Frequency Domain and Comparative Analysis using Walsh and Hadamard transform

A Watermarking Technique with Chaotic Fractional S-Box Transformation

In this paper, the system of non-linear ordinary differential equations which defines a continuous-time dynamical system that shows the fractal characteristics of attractor is used to construct chaotic S-box. In this new digital watermarking technique the priority is of importance of robustness along with chaos to create confusion. The inclusion of chaos along with watermarking in frequency domain ensures robustness. As we have proposed a frequency domain watermarking as which we embed watermark into the low or middle frequencies, these changes will be spread all over the image. The strength of fractional S-box is evaluated with the help of bit independence criterion, nonlinearity analysis, strict avalanche criterion, linear approximation probability and differential approximation probability. Additionally, some security analyses in the form of correlation, contrast, energy, entropy, homogeneity, mean square error and peak signal to noise ratio are performed for validity of proposed watermarking scheme. The confidence measure after these analyses indicates the survival aligned with malicious attacks like noise, cropping and compression.

Dual plane multiple spatial watermarking with self-encryption

Watermarking has established itself as a promising solution in the context of digital image copyright protection. Frequency domain watermarking is mainly preferred due to associated robustness and perceptual issues but requires a large amount of computation. On the other hand spatial domain watermarking is much faster but lacks when robustness is concerned. In this paper a block based spatial domain watermarking technique for color images is proposed that is fast and robust. Two-way embedding introduced in the paper provides capability to previously estimate perceptual degradation in host image due to watermark embedding. Multiple watermarking in two component images is used to achieve better imperceptibility and better robustness. Self-encryption introduced aims to remove dependency over external secret key however optional encryption with random secret keys is proposed for providing better security. Proposed embedding technique is an effort to achieve proper balance between robustness and quality degradation of image. Experiments suggest proposed method is robust against processing attacks such as spatial filtering transformations image enhancement and loss compression.

Embedding Image ROI Watermark Into Median DCT Coefficients

Algorithms of digital image watermarking are broadly classified in spatial domain watermarking and frequency domain watermarking. Spatial domain watermarking techniques have low bit capacity and low robustness to different types of attacks, such as compression, cropping, noise addition and affine transforms. However, frequency domain watermarking proved robustness to watermark attacks, therefore watermarking scientists paid attention to such techniques in particular to Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) since they can be used in different multimedia standards such as MPEG-4 and JPEG2000. In this paper, a watermarking approach based on DCT is introduced. The image is divided into 8 x 8 blocks and DCT is applied on each block. All median DCT coefficients for all blocks are collected and compared with a selected ROI DCT coefficient; the block coefficient with the least absolute difference will be used for embedding. Results showed high robustness and imperceptibility when the median coefficients are used compared to embedding in other coefficients.