A Gestalt-Guided Heuristic Boundary Follower for X-Ray Images of Lung Nodules

A ``piecewise heuristic'' follower of the boundaries of difficult-to-notice nonoverlapping blobs in digitized images is described. The technique was tested on 324 X-ray images of candidate lung nodules from eight radiographs with good results. This technique is several times faster than earlier detectors of the boundaries of lung nodules, while maintaining good fidelity of the detected boundaries.