Real time contour tracking with a new edge detector

In this paper, a new system for real time contour tracking is presented. If a rough contour of the desired structure is available on the first image of a sequence, the system can automatically outline the contours on the subsequent images at video rate. The method we used is based on a new edge detector which was obtained by the generalization of the first order absolute central moment operator. The new algorithm proved to be very robust to noise and fast enough to be implemented in real time. The contour tracking procedure was implemented on an integrated software/hardware platform composed of a personal computer equipped with a digital signal processing board. The system can capture an analog video signal with a resolution of 512512 pixels, 25 frames/s, process the data and display the results in real time. A graphical user interface is also available to interact with the system. Tests on images of the descending thoracic aorta and of a carotid, recorded by echocardiography, are reported. The cross-sectional area of the aorta and the diameter of the carotid were computed in real time and plotted on the user interface. The system proved to be a useful tool for the investigation of vascular mechanisms.