Extraction of Blood Vessels in Retinal Images Using Four Different Techniques

<table>Effect of image background on vessel tree extraction, (a) original Image, (b) background modified image, (c) automatic thresholding of image in (a), (d) automatic thresholding of image in (b).</table>

Journal of Medical Engineering

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Figure 13

Figure 13: Extraction of Blood Vessels in Retinal Images Using Four Different Techniques 