Improved DCT-Based Watermarking through Particle Swarm Optimization. - Chih-Chin Lai; Wei-Shun Wang; Ci-Fong Jhan (ICCCI (3), 2010)

Digital image watermarking using DCT and z-score transform. - Chih-Chin Lai; Ci-Fong Jhan; Wei-Shun Wang (ICMLC, 2010)