3. Non-local means filter: This is an image de-noising algorithm. The non-local means filter calculates a mean of all the image pixels, weighed by how comparable these pixels are to the target pixel. Consequently, loss of detail in the image is minimized while achieving higher image clarity. We implemented non-local means filtering in MATLAB and used a filter value of 0.2 and 0.5 for the neutron and X-ray images respectively.