Contour Tracking When Two Gray-Level Discontinuities Are Close to Each Other
Vascular measurements are indispensable to quantify important indexes of cardiovascular risk and image processing systems are needed to automatically track the vascular structures through sequences of echographic images. Given a starting contour c n on frame f n , a contour tracking algorithm is generally based on the application of a mathematical operator at the points of c n and on an iterative procedure which brings such points to the respective points of the contour c n + 1 on the subsequent frame f n + 1. In this paper, the performances of a mathematical operator which looks for similar regional gray level distributions are compared to those of an edge detection operator. The paper shows that when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both operators should be used sequentially.
KeywordsContour Tracking Vascular Images Ultrasound Imaging