The flowchart of the postprocessing procedures. The top row presented the prediction maps after each step, and the bottom row showed the corresponding procedures on the fundus photographs. (a) The raw prediction map coming from the lightweight U-Net structure and the corresponding fundus image. (b) The prediction map and the fundus image after an elliptic region around the optic disc were covered. (c) The prediction map and the fundus image after the optic disc and macula region were covered.