Issue No. 08 - August (2009 vol. 31)
Wenhe Liao , Nanjing University of Aeronautics and Astronautics, Nanjing
Kai-Kuang Ma , Nanyang Technological Univeristy, Singapore
Baojiang Zhong , Nanjing University of Aeronautics and Astronautics, Nanjing
The curvature scale-space (CSS) technique is suitable for extracting curvature features from objects with noisy boundaries. To detect corner points in a multiscale framework, Rattarangsi and Chin investigated the scale-space behavior of planar-curve corners. Unfortunately, their investigation was based on an incorrect assumption, viz., that planar curves have no shrinkage under evolution. In the present paper, this mistake is corrected. First, it is demonstrated that a planar curve may shrink nonuniformly as it evolves across increasing scales. Then, by taking into account the shrinkage effect of evolved curves, the CSS trajectory maps of various corner models are investigated and their properties are summarized. The scale-space trajectory of a corner may either persist, vanish, merge with a neighboring trajectory, or split into several trajectories. The scale-space trajectories of adjacent corners may attract each other when the corners have the same concavity, or repel each other when the corners have opposite concavities. Finally, we present a standard curvature measure for computing the CSS maps of digital curves, with which it is shown that planar-curve corners have consistent scale-space behavior in the digital case as in the continuous case.
Scale space, corner detection, curve evolution, CSS, digital curves, curvature, discrete curvature, shrinkage rate, evolution trajectory, dual trajectory.
Wenhe Liao, Kai-Kuang Ma, Baojiang Zhong, "Scale-Space Behavior of Planar-Curve Corners", IEEE Transactions on Pattern Analysis & Machine Intelligence, vol. 31, no. , pp. 1517-1524, August 2009, doi:10.1109/TPAMI.2008.295