Meaningful Watermark Research Articles

Tamper detection technique for document images using zero watermarking in wavelet domain

Existing tamper detection techniques for document images use the textual information of the image to create a zero watermark. These techniques cannot authenticate a document image if the image is tampered with in non-textual regions. In order to resolve this problem, a tamper detection technique for document images is proposed using the concept of zero watermarking. The input document image is transformed by applying lifting wavelet transform to get its subbands. These subbands are further partitioned into non-overlapping blocks of the same size. Features of each blocks are extracted to create a zero watermark. This watermark is combined with the key watermark in order to create a meaningful watermark. This meaningful watermark is stored by a trusted authority. On the receiver side, the meaningful watermark is compared to the watermark generated using tampered image to check the authenticity of the cover image. The tampered regions of the cover image can also be localized using this technique. The experimental results demonstrate the effectiveness of the technique in comparison to the existing authentication techniques.

Dual DCT-DWT-SVD digital watermarking algorithm based on particle swarm optimization

Robust invisible watermarking plays an important role in copyright protection. Such watermarking has high requirements for robustness and security, and transparency and capacity cannot be ignored. Although there are many algorithms using singular value decomposition, most algorithms do not take security and reliability into account. Moreover, a meaningful watermark cannot be extracted under some attacks, resulting in the failure of copyright protection. In this paper, combined with particle swarm optimization (PSO), a secure and robust dual-embedded watermarking algorithm is proposed. First, the watermark image is encrypted by the generalized Arnold transform, then the original host image and the encrypted watermark image are processed by discrete cosine transform and multi-level discrete wavelet transform, and the singular values of the watermark image are embedded into the low-frequency and high-frequency regions of the host image, respectively. In addition, the embedding factor matrices are optimized by PSO. The simulation results based on the normal and medical host and watermark images show that the algorithm can meet the four basic characteristics of the watermarking algorithm. Moreover, the proposed watermarking algorithm has high capacity and good robustness, and can extract watermark with good visual effect under most attacks, so it can be used in copyright protection.

A novel zero‐watermarking approach of medical images based on Jacobian matrix model

AbstractEnsuring the medical images authenticity becomes an essential need. This need has to keep of course two factors: (i) high robustness and (ii) low complexity in term of processing. A zero‐watermarking scheme could be a practical solution for this matter. This paper proposes a zero‐watermarking algorithm to assure the authenticity of the transmitted medical images through an e‐healthcare network. The targeted image is partitioned into 8 × 8 non‐overlapping blocks, and the Jacobian matrix model is used to construct a meaningful watermark. In order to reduce the complexity, our model does not encrypt the watermark image. The experiment results show a remarkable efficiency of the proposed model in terms of similarity, error probability, and robustness against a variety of geometric and non‐geometric attacks. Copyright © 2017 John Wiley & Sons, Ltd.

A robust watermarking algorithm based on QR factorization and DCT using quantization index modulation technique

We propose a robust digital watermarking algorithm for copyright protection. A stable feature is obtained by utilizing QR factorization and discrete cosine transform (DCT) techniques, and a meaningful watermark image is embedded into an image by modifying the stable feature with a quantization index modulation (QIM) method. The combination of QR factorization, DCT, and QIM techniques guarantees the robustness of the algorithm. Furthermore, an embedding location selection method is exploited to select blocks with small modifications as the embedding locations. This can minimize the embedding distortion and greatly improve the imperceptibility of our scheme. Several standard images were tested and the experimental results were compared with those of other published schemes. The results demonstrate that our proposed scheme can achieve not only better imperceptibility, but also stronger robustness against common signal processing operations and lossy compressions, such as filtering, noise addition, scaling, sharpening, rotation, cropping, and JPEG/JPEG2000 compression.

Blind Watermarking Algorithm Based on Wavelet-Transform & Fractal Self-Similarity

An algorithm for embedding a meaningful 2-bit watermark image in carrier image is proposed by using Zigzag image scrambling based on discrete wavelet transform (DWT) and fractal self-similarity, along the Hilbert fractal curve scan sequence in the intermediate frequency subimage of wavelet decomposition of a carrier image, according to the mask template of Sierpinski carpet. Extracting the embedded watermark does not need the original carrier image and the original watermark image, which is a blind watermark algorithm. By using fractal self-similarity and Sierpinski carpet mask, watermark information can be embedded into the non-central parts of the carrier image repeatedly N times .The algorithm has shown the higher watermark imperceptibility and robustness under cutting and falsifying attacks of image, which is proved to be true by experimental results. The algorithm can be applied in DRM to protect digital image copyright.

Robust Audio Watermarking Algorithm based on General Orthogonal Domain

In this paper, robust audio watermarking algorithm based on general orthogonal domain is proposed. By binary halftone pretreatment, one-dimensional meaningful audio watermarking is pretreated to high-fidelity binary audio. The host audio is raised to 2-dimensional space and divided into multi-sections. Each appropriate section is transformed by the general orthogonal transformation matrix. A bit binary audio watermarking signal is embedded, and the host audio is reduced to onedimensional space. So the host audio with watermarking is gotten. Because of the general orthogonal matrix, the security is higher. Experiments show that the algorithm has big embedding quantity, high security, strong practicability and robustness in enduring common attacks.

Auditory Cryptography Security Algorithm With Audio Shelters

In this paper, auditory cryptography security algorithm with audio shelters is proposed. The meaningful audio watermarking is pretreated to high-fidelity binary audio, and the binary audio is encrypted to n cryptographic audios by (k, n) threshold scheme. Less than k of the cryptographic audios give no information, only synchronized playing k or more than k of the audios the original can be heard directly. The n cryptographic audios are embedded in the corresponding n shelter audios which are pretreated by high-dimensional matrix transformation. Experiments show that the proposed algorithm has strong practicability, high security and robustness in enduring common attacks.

High Capacity Watermark Embedding Based on Invariant Regions of Visual Saliency

A new image watermarking scheme is presented to achieve high capacity information hiding and geometric invariance simultaneously. Visually salient region is introduced into watermark synchronization. The saliency value of a region is used as the quantitative measure of robustness, based on which the idea of locally most salient region (LMSR) is proposed to generate the disjoint invariant regions. A meaningful binary watermark is then encoded using Chinese Remainder Theorem (CRT) in transform domain. Simulation results and comparisons demonstrate the effectiveness of the proposed scheme.

NOVEL SELF-REFERENCE BASED IMAGE WATERMARKING SCHEME

In this paper, a novel image watermarking scheme based on a self-reference technique is proposed. The meaningful watermark is embedded into a gray-level image according to the relation between the constructed reference image and the original host. In order to be robust against Jpeg compression, the reference image should be robust under Jpeg compression. Firstly, the original image is transformed into DCT domain; and then most of the high frequency coefficients are omitted; after the quantization step and inverse DCT transform, we can obtain a robust reference. By considering the relation between the original image and its reference, we can embed the watermark into the host. The watermark extraction process is oblivious. Experimental results under several attacks show good robustness of the proposed scheme. Especially under cropping and Jpeg compression attacks, the watermark can be extracted with only few errors.