A Secure and Robust Image Watermarking System Using Normalization and Arnold Scrambling

This article proposes an image watermarking scheme to improve the robustness and security of watermark against several attacks. To achieve this, image normalization is utilized where affine transformation is applied on the image and which makes it as invariant to geometric transformations. The Lifting Wavelet Transform (LWT) and block based Discrete Cosine Transform (DCT) is applied to the cover image after normalizing an image. Then, the DC coefficients from all blocks are gathered and singular value matrix is constructed using Singular Value Decomposition (SVD). The watermark image is embedded in this singular value matrix after scrambling the image, which increases the security of the proposed scheme. The robustness and invisibleness of the proposed scheme is measured using Peak Signal to Noise Ratio (PSNR), Signal to noise Ratio (SNR) and Structural Similarity (SSIM). The comparison was made with existing schemes and it reveals that the proposed scheme provides high robustness than the existing one.