Extraction of Blood Vessels in Retinal Images Using Four Different Techniques

Figure 15

Comparison of vessel tree extraction with conventional matched and modified matched filtering techniques, (a) image obtained with conventional matched filtering approach, (b) image obtained with modified matched filtering technique (thresholded image obtained after processing with homomorphic filter and matched filter), (c) image obtained after length filtering of image in (a), (d) image obtained after length filtering of image in (b).