Step 1: Define initial estimates for the object function and for the mask.
Step 2: For .., calculate using MART and the mask .
Step 3: Smooth with a low-frequency filter.
Step 4: Calculate values of .
Step 5: If , then go to step 2, otherwise go on to step 6.
Step 6: End.
Algorithm 1: Basic steps of the MART-AP algorithm.