Blind Wavelet Based Watermarking Technique for Image Authentication

The central idea of this paper is to propose an inno vative watermarking scheme which embeds watermark signal into the host image in order to authenticate it. In this novel technique, some pixels are randomly selected from original image, so that all of them have a valid 3x3 neighborhoods. A binary sequence is constructed from those pixels by comparing them against average values of neighborhoods. The binary sequence is then converted into a watermark pattern in the form of a Toeplitz matrix to improve security of watermarking process and is then embedded within the host image. The operation of embedding and extraction of watermark is done in high frequency domain of Discrete Wavelet Transform since small modifications in this domain are not perceived by human eyes. This watermarking scheme deals with the extraction of the watermark information in the absence of original image, hence the blind scheme is obtained. The proposed algorithm is more secure and robust against most of the common image processing attacks. Finally computer simulations demonstrate that the proposed method is better than the recent algorithm proposed in (5) by Lin Q. et al. in terms of Peak Signal to Noise Ratio.