Reconstructed images of a modified Shepp-Logan phantom from 7 sources in a display window [0, 0.5]. From top to bottom in the left panel, the images were reconstructed from full-scan, half-scan and one-third-scan, respectively. From left to right, the images were reconstructed by the classical FBP method, TVM-SD method after 200 iterations (5 TV minimization loops in each main loop), and TDM-STF method after 200 iterations (5 soft-threshold filtering loops in each main loop). And the right panel shows image profiles along the vertical central lines in the left panel, respectively.