International Journal of Computer Science Issues

More than a traditional journal...

A watermarking scheme for digital images based on Particle Swarm Optimization (PSO) in the Discrete Wavelet Transform (DWT) is proposed. The watermark is inserted into the DWT subbands which have the most important coefficients. The robustness of proposed scheme is empowered by applying the PSO. PSO optimizes the imprceptibleness of the watermark and the quality of the watermarked image which results in identifying the optimal / nearly optimal embedding positions. A series of experiments were carried out using different host images with different watermarks under different attacks. It has been shown that the approach is robust against several water-marking attacks that may meet the watermarked image. The efficacy of the proposed scheme is verified by using two basic criteria; the peak signal to noise ratio and the cross-correlation function which are used to measure the quality and strength of the watermark. In conclusion, the experimental results substantiate that PSO in the DWT can improve the quality of the watermarked image effectively, as well as it can yield a watermark that is invisible to human eyes, and robust against common image processing attacks.