I've come across code to calculate a Dice coefficient in imaging segmentation, in which a "smoothing factor" was added to the formula, as below (pseudo-code):
sf = 1
Dice = [2 (A * B) + sf] / [(A + B) + sf]
What would be the purpose of this and its effect on the output of Dice coefficient?
2
should be multiplied by the sum of numerator (intersection), do you agree? $\endgroup$