Implementation steps of Lucy-Richardson deconvolution in MATLAB

I am trying to understand the Lucy-Richardson algorithm implementation in MATLAB, specifically if there is any thresholding being performed as a post-processing step?. I was able to implement a working algorithm, however, there were some contrast differences between my output and MATLAB output.

Could anybody please explain if I am missing something or does MATLAB perform some post-processing to improve the result?

Regards, Ram