Analyzing the performance of watermarking based on swarm optimization methods

Abstract

Digital image watermarking is the process of inserting data into an image. Nowadays, digital watermarks are being recognized as a solution to pro-tect copyright of the digital images. In this study, an attempt has been made to retrieve watermark same as original watermark from the embedded image by Cat Swarm Optimization (CSO) technique. Embedding watermarks in frequency domain can usually be achieved by modifying the least significant bits of the transformation coefficients. Rounding approach is applied frequently to retrieve the hidden watermark in an image differing from the original watermark. Swarm intelligence techniques are proposed to eliminate the rounding errors caused by the simple approach while transferring the image from frequency domain to spatial domain. Results are demonstrated with less computation time, less number of iteration and less PSO time-varying inertia weight factor for CSO method in comparison with Particle Swarm Optimization (PSO).