Effective retinal blood vessels detection using only directional information

We present an effective unsupervised segmentation method that is based only on the use of the direction map built in correspondence of the retinal image by assigning each pixel one out of twelve discrete directions. The segmentation method works on the green channel of RGB retina images and does not require any pre-processing phase. The method has been checked on the DRIVE dataset producing satisfactory results both qualitatively and quantitatively.