Preliminary results on using an extension of gradient method for detection of red lesions on eye fundus photographs

The paper presents an extension of the gradient method for detection of red lesions on images of eye fundus, like a step in an automated system for recognition of diabetic retinopathy. Images of high resolution were corrected for shading and noise and the method was applied by calculating on every pixel the “expanding gradient” of that pixel. This way, a map of the image was obtained and by thresholding conveniently, the interest objects of the image were detected with a certain level of certainty. After removing vessels, optic disc and other objects, each of the remaining objects are studied and the decision of being or not red lesion is taken. From 687 true red lesions included by 47 images of eye fundus, 584 red lesions were found using this method and a number of 106 false red spots were additionally found.