Fig. 1.

Cone photoreceptor segmentation using the quasi-polar transform. (a) Cartesian image containing the cone to segment. (b) Pilot estimate of the cone in (a). (c,d) Polar transformation of (a) and (b), respectively. The black regions in (c) are invalid points that lie outside the image in the Cartesian domain. (e,f) Images (c) and (d) column-wise shifted until the pilot estimate in (d) was flat. (g) Segmentation of (e) using GTDP (magenta). (h) Transformation of the segmentation in (g) back into the Cartesian domain (magenta).