Digital Image Watermarking Based on Genetic Algorithm Approach

Digital watermarking is the process of embedding information into a digital signal. The main issues to be considered during the watermark are robustness and fidelity. Robustness implies the strength of the watermark against various image processing attacks. The fidelity is used to determine the quality of the image after embedding the watermark. The techniques of digital watermarking are based on spatial domain and frequency domain. In this paper a watermarking scheme is implemented based on DWT using Genetic Algorithm. Discovering the locations to embed watermark into cover image can be viewed as an optimization problem. Genetic Algorithm is used to find optimal locations to achieve fidelity. The proposed technique uses Rank and Tournament based selection as a selection operator to find the optimal locations for embedding watermark into the cover image. Attacks are also possible on the watermarked image. Quantitative measures such as PSNR and NC are used to evaluate the quality of each watermarked image.