中文说明：许多研究者采用了加法
English Description：
Many researchers were used the additive method of digital watermarking images which we quote for example Anuradha and Rudresh Pratap Singh (2006) [1]. However, this paper proposes an additive watermarking method by invoking Particle Swarm Optimization (PSO) technique in wavelet domain to improve this scheme of watermarking. To avoid that the watermarking lose its robustness and imperceptibility and extract the watermark under the perfect performance, PSO is fused with the method proposed in [1] which used to insert the watermark