Background:
Nowadays information security is one of the biggest issues of social networks. 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 authentication of multimedia.
Objective:
We aim to create a new and more robust image watermarking technique to prevent illegal copying, editing and
distribution of media.
Method :
The watermarking technique proposed in this paper is non-blind and employs Lifting Wavelet Transform on the
cover image to decompose the image into four coefficient matrices. Then Discrete Cosine Transform is applied which
separates a selected coefficient matrix into different frequencies and later Singular Value Decomposition is applied. Singular Value Decomposition is also 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 Discrete Cosine 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 and filtering. The performance comparison is evaluated based on Peak Signal to Noise Ratio, Structural Similarity Index Measure, and Normalized Cross-Correlation.
Conclusion:
The experimental results prove that the proposed method performs better than other state-of-the-art techniques and can be used to protect multimedia ownership.
Design of fractional order differentiator using type-III and type-IV discrete cosine transform