Signal and Data Processing

In this paper, a new unsupervised algorithm for automatic retinal blood vessel extraction is presented. A pre-processing step is introduced to eliminating optic disk and back ground noise. Blood vessel highlighting is prepared by a new method inspired by simple cells in human visual system. An adaptive threshold is introduced as an activation function of simple cells. Post-processing step is used as a final stage at the output of simple cells to eliminating exudates which is detected as blood vessels. The results on DRIVE database demonstrate that the performance of the proposed algorithm is comparable with state-of-the-art techniques in terms of execution time and extracted vessels.