Locating the optical disc in retinal images

We present a method to automatically outline the optic disc in a retinal image. Our method for finding the optic disc is based on the properties of the optic disc using simple image processing algorithms which include thresholding, detection of object roundness and circle detection by Hough transformation. Our method is able to recognize the retinal images with general properties and the retinal images with variance of unusual properties since the parameters of our method can be flexibly changed by the unusual properties.