Automatic optic disk segmentation in presence of disk blurring

Abstract

Fundus image analysis has emerged as a very useful tool to analyze the structure of retina for detection of different eye-related abnormalities. The detection of these abnormalities requires the segmentation of basic retinal structures including blood vessels and optic disk. The optic disk segmentation becomes a challenging task when the optic disk boundary is degraded due to some deviations including optic disk edema and papilledema. This paper focuses on the segmentation of optic disk in presence of disk blurring. The method proposed makes use of gradient extracted from line profiles that pass through optic disk margin. Initially the optic disk is enhanced using morphological operations and location of optic disk region is detected automatically using vessel density property. Finally, line profiles are extracted at different angles and their gradient is evaluated for the estimation of optic disk boundary. The proposed method has been applied on 28 images taken from Armed Forces Institute of Ophthalmology.