Algorithm 1. Blur Kernel Estimation.

Input: Blurred image, reliable structures and the initial value of k from previous iterations or previous level;

for n = 1 to Itr (Itr: number of iterations) do

Estimate the blur kernel using the reliable structures. (Equation (7))

Refine the blur kernel by solving Equations (10) and (11) alternately.

$k\leftarrow \tilde{k}$;

end for

Output: Blur kernel k.