Fig 2. Examples of adequate, inadequate, and wrong images generated by R-CNN.

(A) Adequate onychomycosis images; a nail plate occupies around 50~80% of the whole picture.

(B) Inadequate nail plate images which include non-standardized nail images such as 1) a partially cut nail, 2) tilted nail, 3) a nail with a foreign substance, 4) unfocussed nail, 5) nail plates that are too small or too large to identify surrounding skin, and 6) image containing two or more nail plates.

(C) Wrong images that included many general objects detected by R-CNN based on the difference between the nail and the background, but not corresponding to either. Objects that had a similar shape to a nail, such as teeth or warts were also generated. A large number of fingers and toes without a nail plate also came out.