Bidimensional retinal blood vessel reconstruction by a new color edge tracking procedure

The authors present a new color edge tracking procedure in order to achieve a bidimensional reconstruction of the retinal blood vessels. The major branches of the reconstructed vessels will serve as landmarks in order to locate the retinal lesions called CytoMegaloVirus (CMV) retinitis, on the color fundus images of patients with acquired immune deficiency syndrome (AIDS). The reconstruction is based on a recursive tracking of the two vessel edges extracted by means of color edge detection. After an interactive selection of the starting edge pixels, the tracking process automatically searches for the side-branches of the major vessel being tracked, providing a tree representation of the vessel vasculature. During the tracking, contour and region information (color of the vessel body) are associated in order to get more accurate extraction.