Comparative Study of Retinal Vessel Segmentation Based on Global Thresholding Techniques

Algorithm 1

Algorithm for CLAHE global-based thresholding technique.

(1) Input the colored retinal image

(2) Compute the gray scale of the colored retinal image

(3) Image preprocessing through CLAHE using (1) and (2)

(4) Enhance image using any of the following smoothing filters:

   (i) Gaussian filter

   (ii) Average filter

   (iii) Adaptive filter

   (iv) Average and Gaussian filters

(5) Segment image using any of the following thresholding techniques:

   (i) Otsu threshold using (9)

   (ii) ISODATA threshold using (10)

(6) Perform background subtraction

(7) Perform morphological operation for noise removal

(8) Obtain segmented vascular network