An optimal image watermarking approach through cuckoo search algorithm in wavelet domain

An evolutionary algorithm, called the cuckoo search (CS), is introduced in this paper for finding the optimal scaling factors (SFs) in digital image watermarking to improve robustness and imperceptibility. It is the first application of the CS technique to the image watermarking problem. The basic idea is to treat digital image watermarking as an optimization problem and then solve it using CS. Apply one/two-level discrete wavelet transform to the host image, then the coefficients of low and high frequency sub bands are modified by embedding the watermark multiplied by SFs. The SFs are optimized using the CS algorithm to obtain the highest possible robustness without compromising with the quality. To investigate the robustness of the scheme several attacks are applied to seriously distort the watermarked image. Empirical analysis of the results has demonstrated the efficiency of the proposed technique.