@string{pattrec="Pattern Recognition"}
@string{elsevier="Elsevier"}
@Article{Horvath-etal2009,
  author =	 {Peter Horvath and Ian Jermyn and Kato, Zoltan and
                  Zerubia, Josiane},
  title =	 {A higher-order active contour model of a `gas of
                  circles' and its application to tree crown
                  extraction},
  journal =	 pattrec,
  year =	 2009,
  publisher =	 elsevier,
  volume =	 42,
  number =	 5,
  pages =	 {699--709},
  month =	 may,
  abstract =	 {We present a model of a `gas of circles': regions in
                  the image domain composed of a unknown number of
                  circles of approximately the same radius. The model
                  has applications to medical, biological,
                  nanotechnological, and remote sensing imaging. The
                  model is constructed using higher-order active
                  contours (HOACs) in order to include non-trivial
                  prior knowledge about region shape without
                  constraining topology. The main theoretical
                  contribution is an analysis of the local minima of
                  the HOAC energy that allows us to guarantee stable
                  circles, fix one of the model parameters, and
                  constrain the rest. We apply the model to tree crown
                  extraction from aerial images of
                  plantations. Numerical experiments both confirm the
                  theoretical analysis and show the empirical
                  importance of the prior shape information.},
  pdf =		 {papers/pattrec2009.pdf},
}