Blood Vessel Extraction in Color Retinal Fundus Images with Enhancement Filtering and Unsupervised Classification

Figure 6

Example results of different filters (Gabor, Gaussian, and Frangi) and binary result.

(a) Color retinal fundus image

(b) Preprocessed gray level intensity image

(c) The top-hat transform of Gabor filter output

(d) The top-hat transform of Gaussian filter output

(e) The top-hat transform of Frangi filter output

(f) Binary result using Gabor filter and K-means