Robust Image Watermarking in Wavelet Domain using RDWT-HD-SVD and Whale Optimization Algorithm. - Guang-Da Zhang; Ze-Xin Zhang; Jing-You Li; Yang Guo; Hao Ding; Xiao-Tian Xi; Rong-Le Wei; Hai-Chuan Yu; Yi-Chen Han (Circuits Syst. Signal Process., 2025)