Table 1: Variance of the noisy images in Figure 13 based on the noise-free images in Figure 7.

Algorithm value FDK 1.3986 Hu’s 1.3999 T-FDK 0.27443 CFDKW-1 0.24365 CFDKW-2 0.26443 Zhu et al.’s 1.3999 EM-1 0.24365 EM-2 0.26443