Figure 4

Typical errors in automatic counting. Sample clips with manually counted photoreceptors (tagged with green or blue dots, respectively) (A,C,E,G,I) will be compared with automatic counts obtained with Algorithm 1 (counted features dyed in red) (B,D,F,H,J). In the latter, the arrows point to occasional artifactual errors. (A,B) Lynx, No. 8: Adjacent cells have been merged and counted as a single one. (C,D) Pangolin, No. 12: Single cells are counted twice. (E,F) Agouti, No. 16: Background features (clustered melanin granules) and outer segment fragments are counted as cells. (G,H) Jaguar, No. 11: Parts of horizontal cells in the background are counted as S-cones. Note that, however, S-cones and horizontal cells are generally well differentiated, and even S-cones positioned directly above a horizontal cell are correctly recognized (middle left). (I,J) Orangutan, No. 2: Parts of vessels are counted as S-cones. In general, however, S-cones and vessels are well differentiated, and even S-cones positioned directly above a vessel are correctly recognized (left and middle part of the clip).