Optic Disk Localization for Gray-Scale Retinal Images Based on Patch Filtering

Abstract

In this paper, an optic disk (OD) localization method is proposed for the retinal images based on a novel patch filtering approach. The patch filtering has been performed sequentially based on clustering in two stages. In the first stage, the patches are selected exploiting an 'isotropic' measure based on the ratio of maximum and minimum eigenvalues of the moment matrix representing the structure tensor. In the second stage, the patch filtering is based on the saliency measure. Finally, the optic disk is located from the centroids of the selected patches. Promising results are obtained for the low-contrast pathological retinal images using STARE database providing high localization accuracy.