Robust Retinal Blood Vessel Segmentation Based on Reinforcement Local Descriptions

Figure 5

Examples of line sets. We select four kinds of points: on the central of vessel (P1), on the edges of vessel (P2), above the vessel (P3), and under the vessel (P4) in green channel image (a). All searching lines in all directions for line set one and line set two are shown in (b) and (c). Searching step is starting from the central pixel and along these lines in all direction. The corresponding line sets of each pixel in local area are shown. (b1), (b2), (b3), and (b4) are the line sets one of P1, P2, P3, and P4. (c1), (c2), (c3), and (c4) are the line sets two for P1, P2, P3, and P4.