Extraction of Retinal Blood Vessels by Using an Extended Matched Filter Based on Second Derivative of Gaussian

We propose a novel extension of matched filter approach by applying contrast-limited adaptive histogram equalization in pre-processing module and second derivative of Gaussian based matched filter to achieve a better retinal blood vessel structure. Proposed approach also concentrates towards extraction of thin as well as thick retinal blood vessels. The experimental results obtained for both DRIVE and STARE databases confirms that the proposed method has a higher true positive rate (sensitivity) as compared with other available retinal blood vessel segmentation approaches in literature. Further, the performance of the proposed method is also better for the extraction of pathological retinal images.