Self-recovery Fragile Watermarking Research Articles

Cryptanalysis of a Self-Recovery Fragile Watermarking Scheme

Cryptanalysis of a Self-Recovery Fragile Watermarking Scheme

A Self-Recovery Fragile Image Watermarking with Variable Watermark Capacity

Currently, the watermark capacity of most self-recovery fragile image watermarking schemes is fixed. That means for smooth regions and texture regions, the length of watermark information is always the same. However, it is impractical since more recovery information is needed for the recovery of texture regions. In this paper, a self-recovery fragile image watermarking with variable watermark capacity is proposed. Based on the characteristic of singular value decomposition (SVD), a new block classification method is introduced. The image blocks are classified into smooth blocks and texture blocks. For smooth blocks, the average pixel values are adopted as the recovery information to recover the tampered blocks, while for texture blocks, the quantized and coded DCT coefficients are adopted as the recovery information. After encrypted by binary pseudo-random sequence, the recovery watermark of each block is embedded into its mapping block. In the detection side, the three-level detection mechanism is applied to detect and locate the tampered regions. The experimental results prove that the proposed method achieves good tamper detection results, and the recovered image has better image quality than other self-recovery fragile watermarking methods.

Review of Some Existing Work for Self-Recovery Fragile Watermarking Algorithms

This paper covers brief study about some of the latest research trends in self-recovery fragile watermarking algorithms. Fragile watermarking techniques aim to detect modifications to images that are sensitive to any changes, which they are intolerant of even a one-bit alteration. It is desirable to be able to locate the modified areas when a portion of the original content is replaced with other information. Therefore, fragile watermarks are intended for checking the integrity and authenticity of digital contents. Self-recovery means that some significant feature obtained from a selected image itself as a watermark by modifying the pixel values of the original image (host). Once the picture is modified by other users, which has been inserted watermark can be used for tamper detection and recovery images. In this research, we have studied that generally, embedding algorithm for tamper recovery includes three main steps: preprocess the original image and extract important information from it, reorder and embed important information into spatial or frequency domain of host image, and extract the important information from stego-image and use it to recover damaged parts as tamper occurs.

Performance Analysis of a Block-Neighborhood-Based Self-Recovery Fragile Watermarking Scheme

In this paper, we present the performance analysis of a self-recovery fragile watermarking scheme using block-neighbor- hood tamper characterization. This method uses a pseudorandom sequence to generate the nonlinear block-mapping and employs an optimized neighborhood characterization method to detect the tampering. Performance of the proposed method and its resistance to malicious attacks are analyzed. We also investigate three optimization strategies that will further improve the quality of tamper localization and recovery. Simulation results demonstrate that the proposed method allows image recovery with an acceptable visual quality (peak signal-to-noise ratio (PSNR) as 25 dB) up to 60% tampering.

A novel self-recovery fragile watermarking scheme based on dual-redundant-ring structure

In this paper, we propose a novel self-recovery watermarking scheme based on dual-redundant-ring structure (DRRS). All blocks of target image form a ring in a manner that the watermark of an image block is hidden in 1-LSB (least significant bit) of its next block N 1, and the copy of this watermark is embedded into 2-LSB of another block whose position is determined by the position of N 1. The validity of test image block is determined by comparing the number of inconsistent blocks in the block-neighborhood with that of its mapping block. Other detection result is generated in the same way comparing test block with copy block of its next block. The fusion of two detection marks improves tamper detection accuracy, while two copies of watermark provide a second chance for tamper recovery. Experimental results demonstrate that the proposed algorithm is superior to the state of the art of tamper detection and tamper recovery and could keep high security strength.

A self-recovery fragile watermarking scheme for image authentication with superior localization

To address the problems of the inferior localization and high probability of false rejection in existing self-recovery fragile watermarking algorithms, this paper proposes a new self-recovery fragile watermarking scheme with superior localization, and further discusses the probability of false rejection (PFR) and the probability of false acceptance (PFA) of the proposed scheme. Moreover, four measurements are defined to evaluate the quality of a recovered image. In the proposed algorithm, the original image is divided into 2×2 blocks to improve localization precision and decrease PFR under occurrence of random tampering. The PFR under occurrence of region tampering can be effectively decreased by randomly embedding the water-mark of each block in conjunction with a novel method of tamper detection. Compared with the current self-recovery fragile watermarking algorithms, the proposed scheme not only resolves the tamper detection problem of self-embedding water-marking, but also improves the robustness against the random tampering of self-embedding watermarking. In addition, the subjective measurements are provided to evaluate the performance of the self-recovery watermarking schemes for image authentication.