@techreport{TR-IC-02-12,
  number = {IC-02-12},
  author = {R.A. Lotufo and A.X. Falcão and F. Zampirolli},
  title = {{IFT}-Watershed From Gray-Scale Marker},
  month = {September},
  year = {2002}, 
  institution = {Institute of Computing, University of Campinas},
  note = {In English, 17 pages.
    \par\selectlanguage{english}\textbf{Abstract}
     The watershed transform and the morphological reconstruction are
     two of the most important operators for image segmentation in the
     framework of mathematical morphology. In many situations, the
     segmentation requires the classical watershed transform of a
     reconstructed image. In this paper, we introduce the
     IFT--watershed from gray scale marker - a method to compute at
     the same time, the reconstruction and the classical watershed
     transform of the reconstructed image, without explicit
     computation of any regional minima. The method is based on the
     Image Foresting Transform (IFT) - a unified and efficient
     approach to reduce image processing tasks to a minimum-cost path
     forest problem in a graph. As additional contributions, we
     demonstrate why other reconstruction algorithms are not
     watersheds, and present a family of simple, yet efficient
     IFT-based watershed algorithms: classical, watershed from labeled
     marker, from binary marker with on-the-fly labeling, and from
     gray scale marker with on-the-fly labeling and bounded cost.
  }
}