Figure 2.

Representative case. (A) Image cropped to a rectangle of 20° wide and 20° high with the fovea in the midpoint. (B) Blurring and binarization. (C) Erosion and dilation. (D) Sixty-four half lines from the fovea every π/32 radians. (E) Two intersections between the line and the AF ring (II, inner intersection; OI, outer intersection). (F) The inner border of the AF ring: interpolations with cubic splines between IIs. (G) The outer border of the AF ring: interpolations with cubic splines between OIs. (H) Concentric curves outside and inside the AF ring at 1° intervals. (I) TD of HFA (10-2) superimposed on the binary image.