Proposed Watermarking Method Research Articles

Semi-fragile spatial watermarking based on local binary pattern operators

Local binary pattern (LBP) operators, which measure the local contrast within a pixel's neighborhood, have been successfully applied to texture analysis, visual inspection, and image retrieval. In the paper, we present a novel semi-fragile spatial watermarking method based on LBP operators by using the local pixel contrast for the embedding and extraction of watermarks. We also propose a general framework for multi-level image watermarking. Experimental results show that the proposed watermarking methods are robust against commonly-used image processing operations, such as additive noise, luminance change, contrast adjustment, color balance, and JPEG compression. At the same time, they achieve good invisibility, fragility, and image tamper detection and localization with less computational cost.

Blind and robust audio watermarking scheme based on SVD–DCT

Singular value decomposition (SVD) is a new and important transform technique in robust digital watermarking due to its different properties from the traditional transforms such as Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). In this paper, we propose a new, blind and robust audio watermarking scheme based on SVD–DCT with the synchronization code technique. We embed a binary watermark into the high-frequency band of the SVD–DCT block blindly. Chaotic sequence is adopted as the synchronization code and inserted into the host signal. Experimental results show that the proposed watermarking method is comparable to, if not, better than SVD based method and several selected typical audio watermarking methods, even in the presence of various common signal processing attacks.

Multiple Binary Images Watermarking in Spatial and Frequency Domains

Editing, reproduction and distribution of the digital multimedia are becoming extremely easier and faster with the existence of the internet and the availability of pervasive and powerful multimedia tools. Digital watermarking has emerged as a possible method to tackle these issues. This paper proposes a scheme using which more data can be inserted into an image in different domains using different techniques. This increases the embedding capacity. Using the proposed scheme 24 binary images can be embedded in the DCT domain and 12 binary images can be embedded in the spatial domain using LSB substitution technique in a single RGB image. The proposed scheme also provides an extra level of security to the watermark image by scrambling the image before embedding it into the host image. Experimental results show that the proposed watermarking method results in almost invisible difference between the watermarked image and the original image and is also robust against various image processing attacks.

A Robust Image Watermarking in the Joint Time-Frequency Domain

With the rapid development of computers and internet applications, copyright protection of multimedia data has become an important problem. Watermarking techniques are proposed as a solution to copyright protection of digital media files. In this paper, a new, robust, and high-capacity watermarking method that is based on spatiofrequency (SF) representation is presented. We use the discrete evolutionary transform (DET) calculated by the Gabor expansion to represent an image in the joint SF domain. The watermark is embedded onto selected coefficients in the joint SF domain. Hence, by combining the advantages of spatial and spectral domain watermarking methods, a robust, invisible, secure, and high-capacity watermarking method is presented. A correlation-based detector is also proposed to detect and extract any possible watermarks on an image. The proposed watermarking method was tested on some commonly used test images under different signal processing attacks like additive noise, Wiener and Median filtering, JPEG compression, rotation, and cropping. Simulation results show that our method is robust against all of the attacks.

Robust Image Watermarking Using Adaptive Structure Based Wavelet Tree Quantization

This work presents a novel robust wavelet-tree-based watermarking method based on structure-based quantization. Wavelet-trees are arranged into super-trees. The watermark bits are then embedded into the super-trees by using the proposed structure-based quantization method. Next, the super-trees are quantized into a significant structure according to these bits. The quantized super-tree has a stronger statistical characteristic than the unquantized super-tree. Based on this characteristic, the watermark bits could be extracted robustly after an image distortion attack. Finally, an adaptive method is developed to raise the PSNR value. Compared with Wang et al. [17] method, the proposed adaptive method increases PSNR about 5.83 dB. The proposed method also has a higher maximum number of watermark bits than other methods, thus increasing the capacity for embedding. Besides, its computation load is low. Experimental results demonstrate that the proposed watermarking method using adaptive structure-based wavelet-tree quantization performs well in JPEG compression, filtering (Gaussian filter, median filter and sharpen) and geometric attacks (pixel shifting and rotation). In addition, it is very robust against multiple watermark attacks.

Wavelet Packets-Based Blind Watermarking for Medical Image Management

The last decade has witnessed an explosive use of medical images and Electronics Patient Record (EPR) in the healthcare sector for facilitating the sharing of patient information and exchange between networked hospitals and healthcare centers. To guarantee the security, authenticity and management of medical images and information through storage and distribution, the watermarking techniques are growing to protect the medical healthcare information. This paper presents a technique for embedding the EPR information in the medical image to save storage space and transmission overheads and to guarantee security of the shared data. In this paper a new method for protecting the patient information in which the information is embedded as a watermark in the discrete wavelet packet transform (DWPT) of the medical image using the hospital logo as a reference image. The patient information is coded by an error correcting code (ECC), BCH code, to enhance the robustness of the proposed method. The scheme is blind so that the EPR can be extracted from the medical image without the need of the original image. Therefore, this proposed technique is useful in telemedicine applications. Performance of the proposed method was tested using four modalities of medical images; MRA, MRI, Radiological, and CT. Experimental results showed no visible difference between the watermarked and the original image. Moreover, the proposed watermarking method is robust against a wide range of attacks such as JPEG coding, Gaussian noise addition, histogram equalization, gamma correction, contrast adjustment, and sharpen filter and rotation.

다중 복호화 키들을 이용한 영상 워터마크 방법

In this paper, we propose an image watermark method using multiple decoding keys. The advantages of this method are that the multiple original images are reconstructed by using multiple decoding keys in the same watermark image, and that the quality of reconstructed images is clearly enhanced based on the idea of Walsh code without any side lobe components in the decoding process. The zero-padded original images, multiplied with random-phase pattern to each other, are Fourier transformed. Encoded images are then obtained by taking the real-valued data from these Fourier transformed images. The embedding images are obtained by the product of independent Walsh codes, and these spreaded phase-encoded images which are multiplied with new random-phase images. Also we obtain the decoding keys by multiplying these random-phase images with the same Walsh code images used in the embedding images. A watermark image is then made from the linear superposition of the weighted embedding images and a cover image, which is multiplied with a new independent Walsh code. The original image is simply reconstructed by the inverse-Fourier transform of the despreaded image of the multiplication between the watermark image and the decoding key. Computer simulations demonstrate the efficiency of the proposed watermark method with multiple decoding keys and a good robustness to the external attacks such as cropping and compression.

Watermarking Spectral Images with Three-Dimensional Wavelet Transform Subject to Various Illumination Conditions

Digital imaging continues its expansion into various applications. Spectral images are becoming more popular as one field of digital imaging. At the same time, the economic and security aspects in the utilization of images are finding increased emphasis. In this study the authors apply a watermarking method for spectral images, whereby embedding is based on the three-dimensional wavelet transform. The authors study the influence of illumination to the watermarked images. The authors also define how to estimate an unknown illuminant. Experiments were performed on a dataset of 13 spectral images. These experiments indicate that the illumination in spectral images should be established before watermarking, owing to the properties of the illuminants. Using the proposed watermarking method, the embedded watermark is also robust towards lossy compression. Guidelines for the parameter selection for watermarking with the proposed approach are given.

A Main Object-oriented Projective Invariant Image Watermarking Approach

Digital watermarking is a technology that enables to protect distributed digital content from unauthorized reuse. Robust watermarks must be able to survive a range of geometrical attacks, such as image resizing, cropping, translation, rotation, scaling, smoothing, filtering, and simplification. In the current paper, we extend the existing approaches that are partially based on image invariant features by introducing new image invariant features and exclusively using them. The proposed watermarking method is based on a combination of image processing techniques, theory of geometry, multiple image invariant features, and public key encryption. Experimental results show that the use of such combination of techniques allowed for securing the embedded watermark and for success in image watermark's recovery, even if images were exposed to several geometrical attacks.

Transparent robust information hiding for ownership verification

For copyright protection, the robustness of a watermarking scheme against various attacks is an essential requirement. Many proposed robust watermarking schemes may achieve good robustness but at the expense of sacrificing the good quality of the watermarked image. This work, therefore, proposes a transparent robust watermarking scheme, which embeds the watermark (or the secret information) adaptively in the discrete cosine transform (DCT) domain. The proposed scheme is blind as the original image is not needed, and only an image-dependent dual key containing the watermark locations and the scaling factors is required for watermark extraction. This content adaptive replacement embedding technique can guarantee preservation of good visual quality of a watermarked image. The watermarking scheme is shown to be highly robust for a wide range of attacks, including JPEG compression, quantization, additive noise, rotation, cropping, scaling, and filtering. Compared with other existing DCT-domain watermarking methods, the proposed watermarking method can achieve higher robustness performance, while retaining better quality of the watermarked image.

A public verifiable copy protection technique for still images

It is well known that a digital signature scheme and digital timestamp are two well-defined security methods for copyright protection. However, these techniques are not suitable for directly dealing with digital images. For this reason, digital watermarking has received considerable attention for copyright protection. Unfortunately, there are still some challenges in the proposed watermarking schemes. Here, we will introduce cryptographic tools into watermarking, in such a way that both the advantages of cryptographic tools and digital watermarking are available. The publicly verifiable property and tolerant distortion property are therefore possible. Based on this idea, a lossless and robust copyright-protection scheme, distinct from conventional watermarking techniques, is proposed. Our scheme is strong enough to resist common image processing, geometric distortions and some intentional attacks. Some of the attacks are still challenges for the proposed watermarking methods. A series of experiments are conducted to prove the robustness property. The StirMark and unZign attacks are adopted as benchmark verification.

Polar co-ordinates shape adaptive discrete transform-based watermarking scheme for arbitrarily-shaped object

A new watermarking scheme for arbitrarily-shaped image is proposed. Using co-ordinates conversion to log-polar and polar co-ordinates shape adaptive discrete transform (PSADT), the proposed watermarking method can be applied to any arbitrarily-shaped image such as MPEG-4 VOP and is much more robust to geometrical attacks than conventional ones.

Digital rights management and watermarking of multimedia content for m-commerce applications

E-commerce has become a huge business and a driving factor in the development of the Internet. Online shopping services are well established and will, with the advent of evolved 2G and 3G mobile networks, soon be complemented by their wireless counterparts. Furthermore, online delivery of digital media, such as MP3 audio or video, is very popular today and will become an increasingly important part of e-commerce and mobile e-commerce (m-commerce). However, a major obstacle for digital media distribution and associated business is the possibility of unlimited consecutive copying in the digital domain, which threatens intellectual property rights (e.g., copyrights). Digital rights management systems are required to protect rights and business. DRM systems typically incorporate encryption, conditional access, copy control mechanisms, and media identification and tracing mechanisms. Watermarking is the technology used for copy control and media identification and tracing. Most proposed watermarking methods use a so-called spread spectrum approach: a pseudo-noise signal with small amplitude is added to the host signal, and later on detected using correlation methods. A secret key is used to ensure that the watermark can only be detected and removed by authorized parties. Thus, watermarking is an essential component of modern DRM systems. Several standardization bodies are involved in DRM standardization. Some examples, (MPEG-4, SDMI, and DVD), are discussed in this article. Watermarking as an enabling technology is especially highlighted. Furthermore, the relation between DRM and m-commerce, and the impact on business models for m-commerce are discussed. A common experience today is that Internet e-commerce applications cannot always easily be adapted for mobile telecommunications systems. We emphasize, however, that DRM and watermarking can benefit from the additional information available in mobile telecommunications systems, and can thus help to improve rights management for digital media delivery.

Multimedia watermarking techniques

Multimedia watermarking technology has evolved very quickly during the last few years. A digital watermark is information that is imperceptibly and robustly embedded in the host data such that it cannot be removed. A watermark typically contains information about the origin, status, or recipient of the host data. In this tutorial paper, the requirements and applications for watermarking are reviewed. Applications include copyright protection, data monitoring, and data tracking. The basic concepts of watermarking systems are outlined and illustrated with proposed watermarking methods for images, video, audio, text documents, and other media. Robustness and security aspects are discussed in detail. Finally, a few remarks are made about the state of the art and possible future developments in watermarking technology.

ウェーブレット変換に基づく３次元ポリゴンモデルヘの「電子透かし」埋め込み

Recently, much interest is being taken in method to protect the copyright of digital data and preventing illegal duplication of it. However, in the area of CAD/CAM and CG, there are no effective ways to protect the copyright of the 3D geometric models. As a first step to solve the problem, a new digital watermarking method for 3D polygonal models is introduced in this paper. Watermarking is one of the copyright protection methods where an invisible watermark is secretly embedded into the original data. The proposed watermarking method is based on the wavelet transform (WT) for the polygonal model. The watermark can be embedded in the large wavelet coefficient vectors at various resolution levels of the transformed model. The method makes the embedded watermark imperceptible and invariant to the affine transformation. And also makes the control of the geometric error caused by the watermarking reliable. Finally, the effectiveness of the proposed watermarking method is shown through several simulation results.

A variable block-size dot-based watermarking method

We propose a digital watermarking method for still images in the discrete cosine transform (DCT) domain. The adaptive watermark insertion method is employed to increase the invisibility of the inserted watermark in images, in which variable block-size is adopted depending on the characteristics of the region. Experimental results with several test images show that the proposed watermarking method is robust to several common image processing techniques, including Joint Photographic Experts Group (JPEG) compression, lowpass filtering, multiple watermarking, and cropping.

An adaptive digital image watermarking technique for copyright protection

An adaptive digital image watermarking technique is proposed. The proposed method exploits the sensitivity of human eyes to adaptively embed a visually recognizable watermark in an image without affecting the perceptual quality of the underlying host image. In addition, the watermark will still be present if some lossy image processing operations such as low-pass filtering, median filtering, resampling, requantization, and lossy JPEG image compression are applied to the watermarked image. Experimental results show the effectiveness of the proposed watermarking method.