A fast template-based technique to extract optic disc from coloured fundus images based on histogram features

The process of localising and extracting optic disc (OD) from coloured fundus images is of much benefit to the process of diagnosing several eye diseases. This paper presents a fast and robust approach to extract OD by employing the histogram features of the input image and matching it with the histogram of a template image that has no pathological features. These steps result in an image with its own OD region and other pathological structures have more colour intensity than the original image. The proposed method locate part of the OD region first and then expands it to include all the required region based on morphological OD features such as location, area, and colour intensity. The testing results against 1540 fundus images taken from five public databases show that the proposed technique succeeded in extracting OD region from challenging images and it achieved 97.66%, 96.93%, 99.7% for sensitivity, specificity, and accuracy, respectively with a competitive average execution time equal to 2.5s.