“…As noted in [2], fundus images often suffer from nonuniform illumination, poor contrast and noise, thus these images have to go through preprocessing phases. According to [16], the biggest challenges for detection of red lesions are the segmentation of microaneurysms in areas of low contrast and the presence of white lesions in the retina (exudates). It may also be mentioned that microaneurysms and hemorrhages have various sizes and shapes, making it difficult to perform detection of all of them in the image, mainly because the normal structures of the retina, as the fovea and the blood vessels, can be confused with lesions [19].…”