Fig. 8.

Comparison of the TIE algorithm and APBA with noise added. (a) True phase map φ; (b) attenuation map $A_0^2$; (c) the normalized phase contrast image I; (d) recovered phase map with the TIE algorithm, no Tikhonov regularization is used; (e) recovered phase map with the TIE algorithm with Tikhonov regularization; (f) recovered phase map with APBA after 10 iteration steps. In the simulation, the acquired data is assumed to have a level of δ_b = 0.03% detector noise and one pixel misalignment between $A_0^2$ and I horizontally.