Algorithm 1 Pre-processing of RAW (DNG) images taken with a smartphone camera

Intensity or value of YFP, CFP, and Ratio are Y(i,j), C(i,j), and R(i,j) respectively. The pixel position in length and width is i,j. for each pixels intensity (i = 2:length, j = 2:width) if Y(i,j) below 200 then Y(i,j)= 1/4(Y(i − 1,j) + Y(i + 1,j) + Y(i,j − 1) + Y(i,j + 1)) if C(i,j) below 150 then Y(i,j)= 1/4(C(i − 1,j) + C(i + 1,j) + C(i,j − 1) + C(i,j + 1)) if R(i,j) below 1 then Y(i,j)= 1/4(R(i − 1,j) + R(i + 1,j) + R(i,j − 1) + R(i,j + 1)) end