LWT-DCT based Image Watermarking Scheme using Normalized SVD

Background: Nowadays, information security is one of the most significant issues of socialnetworks. The multimedia data can be tampered with, and the attackers can then claim its ownership.Image watermarking is a technique that is used for copyright protection and authenticationof multimedia. Objective: We aim to create a new and more robust image watermarking technique to prevent illegalcopying, editing and distribution of media. Method: The watermarking technique proposed in this paper is non-blind and employs LiftingWavelet Transform on the cover image to decompose the image into four coefficient matrices. ThenDiscrete Cosine Transform is applied which separates a selected coefficient matrix into differentfrequencies and later Singular Value Decomposition is applied. Singular Value Decomposition isalso applied to the watermarking image and it is added to the singular matrix of the cover image,which is then normalized, followed by the inverse Singular Value Decomposition, inverse DiscreteCosine Transform and inverse Lifting Wavelet Transform respectively to obtain an embedded image.Normalization is proposed as an alternative to the traditional scaling factor. Results: Our technique is tested against attacks like rotation, resizing, cropping, noise addition andfiltering. The performance comparison is evaluated based on Peak Signal to Noise Ratio, StructuralSimilarity Index Measure, and Normalized Cross-Correlation. Conclusion: The experimental results prove that the proposed method performs better than otherstate-of-the-art techniques and can be used to protect multimedia ownership.