Proliferation of multimedia on the Internet has led to the need for developing authentication mechanisms. This article proposes a new blind watermarking scheme based on the contents of the image in the discrete wavelet transform domain for image authentication. The host image is discrete wavelet transformed up to second level. The relationship between neighboring wavelet coefficients in each band of the second level decomposition is considered to construct the content-based watermark. The watermark is embedded in the first level mid frequency band, of the discrete wavelet transformed image. The received image is authenticated by extracting the watermark and determining the level of authenticity. This scheme is capable of tolerating content-preserving modifications and detecting content-changing modifications. Experimental results prove the efficiency of the scheme.
Dr. Latha Parameswaran and K., A., “A semi-fragile image watermarking using wavelet inter-coefficient relations”, International Journal of Information Security & Privacy, vol. 1, pp. 61-75, 2007.