Multichannel Retinal Blood Vessel Segmentation Based on the Combination of Matched Filter and U-Net Network

Figure 6

(a, f, k) The grayscale images after preprocessing operation, (b, g, l) small-scale matched filtered images, background extracted by (c, h, m) close operation and (d, i, n) subtraction operation, and (e, j, o) final results. The different samples of (a–e) DRIVE, (f–j) STARE, and (k–o) CHASE_DB1.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(l)

(m)

(n)

(o)