Before revision:  In addition, we can incorporate a box constraint that is reasonable for imaging applications . Numerical schemes are based on the alternating direction method of multipliers (ADMM), and we provide the convergence analysis of all the proposed algorithms (constrained/unconstrained and with/without the box constraint ). Experimental results demonstrate the efficiency of our proposed approaches, showing significant improvements over the state-of-the-art methods in the limit-angle CT reconstruction.
After revision:  In addition, we can incorporate a box constraint that is reasonable for imaging applications , and the convergence for the additional box constraint can also be established. Numerical results on both synthetic and experimental datasets demonstrate the efficiency of our proposed approaches, showing significant improvements over the state-of-the-art methods in the limit-angle CT reconstruction.