Abstract

Detection of Optic disc (OD) in a fundus image is a foremost important step in the process of screening the diabetic retinopathy [1,4,18]. Hard Exudates detection algorithms usually find lot of false positives since the intensity and color distribution of OD will much resemble that of a Hard Exudates region [15,16]. So, most of the Exudates detection algorithms will miss classify the pixels at the OD region as Hard Exudates [2]. In our previous works, we used Genetic Algorithm(GA)[23,24] to find the OD location and size and reduced overall time, even doing the search on the entire problem space and also removed false hard exudates. In this work we are improving Hard Exudates detection accuracy using gradient index mapping technique applied on two similar planes of the RGB. The new algorithm is termed as TWINGRAB use the the two planes of the RGB after proper gradient projection. The database used for this preprocessing is DIARETDB1[10] for evaluation and comparision with the existing methods.