Fig. 4

Visual security evaluation results of objective (blue) and subjective (red) methods for scenario Extended-1 (from the subfigure (a) to (f) in case of Foreman video, x-axis represents different encryptions which result in different MOS in the increasing order and y-axis represents visual security). This shows the evaluation results from the objective metrics (PSNR, MSSIM, LFBVS, LEG, VIF, and STVSM) and the subjective scores of 66 subjects for various encrypted videos additionally considering a special option of the implemented encryption method. By considering the special option, we have 16 encrypted videos which enables us to study the visual security evaluation more detailed as compared to Fig. 3. From the subfigure (a) to (f) in case of Foreman video, x-axis represents different encryptions which result in different MOS in the increasing order and y-axis represents visual security. Similar to Fig. 3, Fig. 4 aims to present how each objective metric correlates with the subjective scores from the human eye’s perception