(a)

(b)

(c)

Figure 13: Slices of Shepp-Logan low contrast phantom at , reconstruction with (a) FDK algorithm, Hu’s algorithm, T-FDK algorithm, (b) CFDKW-1, CFDKW-2, Zhu et al.’s algorithm, (c) EM-1 and EM-2 with added noise. Display window is .