A fractional filter based efficient algorithm for retinal blood vessel segmentation

•A new fractional filter is discussed in this paper.•An unsupervised algorithm for detection of centreline in the retinal image is introduced.•We have introduced an unsupervised algorithm for retinal vessel segmentation that is discussed in this paper.•Performance of proposed algorithm is compared with other existing methods. Simulation results show that performance of the proposed method is better than most of the discussed methods.•Our approach is computationally efficient and applicable in real time.