Finding Center of Optic Disc from Fundus Images for Image Characterization and Analysis

An automated method for center reference point extraction from retinal fundus images is essentially required for an untroubled image mapping in medical image analysis, image registration, and verification. This paper proposes a spadework, revealing a distinct reference point within optic disc in blood vessel structure of the human eye, analysis on which would serve as an efficient preventive measure for any ocular disease and would strengthen the image verification method along with other extracted features of the human eye at low cost. The proposed method includes segmentation from colored fundus images followed by removal of thin and tiny blood vessels which carry very less information. Removal process comes up with a few bounded polygonal structures, named ring near optic disc. From the named structures near optic disc, a cluster of junction points have been found with maximum members and we made a convex hull out of them. Finally, calculating the centroid of the formed convex hull unveils the center of the optic disc. Experiments are done on some publicly available databases called DRIVE, STARE, and VARIA. Experimental results compared to other standard methods are available in the literature.