Constructing Benchmark Databases and Protocols for Medical Image Analysis: Diabetic Retinopathy

Algorithm 2

Pixel-wise evaluation based on pixel scores.

(1) Form a list of tested pixel scores

(2)  for each tested pixel score (curr_pix_score) do

(3)  TN ←0, TP ←0, FN ←0, FP ←0

(4)  for each test image do

(5)   for each test image pixel score do

(6)    if curr_pix_score ≥ pixel score then

(7)     if ground truth pixel assignment = “normal” then

(8)      TN = TN + 1

(9)     else

(10)      FN = FN + 1

(11)     end if

(12)    else

(13)     if ground truth pixel assignment = “abnormal” then

(14)      TP = TP + 1

(15)     else

(16)      FP = FP + 1

(17)     end if

(18)    end if

(19)   end for

(20)  end for

(21)  SN=TPTP+FN (Sensitivity)

(22)  SP=TNTN+FP (Specificity)

(23)   Add new ROC point (𝑥;𝑦) = (1 − SP, SN)

(24)  end for

(25) Return the final ROC curve (all points)