Hariati, Setia, A M H Pardede, and Marto Sihombing. “Application of the DCT Algorithm to Protect Image Files With Key Symbols”. Journal of Artificial Intelligence and Engineering Applications (JAIEA) 3, no. 3 (June 15, 2024): 618–623. Accessed July 7, 2026. https://www.ioinformatic.org/index.php/JAIEA/article/view/456.