Retinal Vessel Diameter Measurement Using Unsupervised Linear Discriminant Analysis

Figure 2

Example of ULDM output showing a vessel cross-section profile (CLRIS, image no. 1, cross-section no. 22) with classified padded intensity values and the decision boundaries between the classes. The horizontal distance between the two points where the decision boundaries cross the vessel edges (approximately at 50% intensity change) was considered as the diameter (18.9 pixels in this example).