学术化英文翻译：经过计算，Fig. 18(b)的信息熵为15.9982，Fig. 18(e)的信息熵为15.9982，熵值均接近16，说明两幅密文图像均近似于随机图像。

After computation, the entropy of Fig. 18(b) is determined to be 15.9982, while the entropy of Fig. 18(e) is also 15.9982. The close proximity of these entropy values to 16 indicates that both encrypted images approximate random images.