M. F. M. . ElBireki, A. A. M. . Ukasha, J. A. R. Dofan, and M. F. L. . Abdullah, “Enhanced Dct Image Watermarking Scheme Based on Zonal Sampling Algorithm Applied With Sspce Contour Extraction, Ramer and Adaptive Triangle Contour Compression Methods”, cest2021 , vol. 6, no. 5، مجلة الجامعة الأسمرية, pp. 877–858, Dec. 2021, Accessed: Jun. 02, 2026. [Online]. Available: https://conf.asmarya.edu.ly/index.php/cest2021/article/view/163