Sorted Pixel Value Difference on Fuzzy Watermarking Scheme

A robust watermark scheme for copyright protection is proposed in the present paper. The present method selects the pixel locations to insert the watermark by a new technique called fuzzy based wavelet approach. The watermark is embedded in the sorted pixel locations of fuzzy based wavelet approach by using pixel value difference method. The proposed approach overcomes the weak robustness problem of embedding the watermark in the spatia domain and also in pixel value difference method. Further the watermark extraction does not require the original image as in the case of many digital watermarking methods. The fuzzy logic approach in the wavelet domain eliminates the requirement of repeated embedding process. The experimental results indicate the high image quality and robustness against various attacks when compared to several approaches

Image Steganography using Hybrid Edge Detector and Ridgelet Transform

Steganography is the art of hiding high sensitive information in digital image, text, video, and audio. In this paper, authors have proposed a frequency domain steganography method operating in the Ridgelet transform. Authors engage the advantage of ridgelet transform, which represents the digital image with straight edges. In the embedding phase, the proposed hybrid edge detector acts as a preprocessing step to obtain the edge image from the cover image, then the edge image is partitioned into several blocks to operate with straight edges and Ridgelet transform is applied to each block. Then, the most significant gradient vectors (or significant edges) are selected to embed the secret data. The proposed method has shown the advantages of imperceptibility of the stego image is increased because the secret data is hidden in the significant gradient vector. Authors employed the hybrid edge detector to obtain the edge image, which increases the embedding capacity. Experimental results demonstrates that peak signal-to-noise (PSNR) ratio of stego image generated by this method versus the cover image is guaranteed to be above 49 dB. PSNR is much higher than that of all data hiding techniques reported in the literature.Defence Science Journal, Vol. 65, No. 3, May 2015, pp.214-219, DOI: http://dx.doi.org/10.14429/dsj.65.787

Sorted Pixel Value Difference on Fuzzy Watermarking Scheme

A robust watermark scheme for copyright protection is proposed in the present paper. The present method selects the pixel locations to insert the watermark by a new technique called fuzzy based wavelet approach. The watermark is embedded in the sorted pixel locations of fuzzy based wavelet approach by using pixel value difference method. The proposed approach overcomes the weak robustness problem of embedding the watermark in the spatia domain and also in pixel value difference method. Further the watermark extraction does not require the original image as in the case of many digital watermarking methods. The fuzzy logic approach in the wavelet domain eliminates the requirement of repeated embedding process. The experimental results indicate the high image quality and robustness against various attacks when compared to several approaches

Wavelet Domain Watermark Detection and Extraction using the Vector-based Hidden Markov Model

Multimedia data piracy is a growing problem in view of the ease and simplicity provided by the internet in transmitting and receiving such data. A possible solution to preclude unauthorized duplication or distribution of digital data is watermarking. Watermarking is an identifiable piece of information that provides security against multimedia piracy. This thesis is concerned with the investigation of various image watermarking schemes in the wavelet domain using the statistical properties of the wavelet coefficients. The wavelet subband coefficients of natural images have significantly non-Gaussian and heavy-tailed features that are best described by heavy-tailed distributions. Moreover the wavelet coefficients of images have strong inter-scale and inter-orientation dependencies. In view of this, the vector-based hidden Markov model is found to be best suited to characterize the wavelet coefficients. In this thesis, this model is used to develop new digital image watermarking schemes. Additive and multiplicative watermarking schemes in the wavelet domain are developed in order to provide improved detection and extraction of the watermark. Blind watermark detectors using log-likelihood ratio test, and watermark decoders using the maximum likelihood criterion to blindly extract the embedded watermark bits from the observation data are designed. Extensive experiments are conducted throughout this thesis using a number of databases selected from a wide variety of natural images. Simulation results are presented to demonstrate the effectiveness of the proposed image watermarking scheme and their superiority over some of the state-of-the-art techniques. It is shown that in view of the use of the hidden Markov model characterize the distributions of the wavelet coefficients of images, the proposed watermarking algorithms result in higher detection and decoding rates both before and after subjecting the watermarked image to various kinds of attacks