@Article{landau1994:subset,
  author =       {Landau, Pierre and Schwartz, Eric L.},
  title =        {Subset warping: {Rubber} sheeting with cuts},
  journal =      {CVGIP: Graphical Models and Image Processing},
  year =         1994,
  volume =       56,
  number =       3,
  pages =        {247--266},
  month =        {May},
  datestr =      199405,
  INSPEC =       4753647,
  abstract =     {Image warping, often referred to as ``rubber
                  sheeting,'' represents the deformation of a domain
                  image space into a range image space. In this paper,
                  a technique which extends the definition of a
                  rubber-sheet transformation to allow a polygonal
                  region to be warped into one or more subsets of
                  itself, where the subsets may be multiply connected,
                  is described. To do this, it constructs a set of
                  ``slits'' in the domain image, which correspond to
                  discontinuities and concavities in the range image,
                  using a technique based on generalized Voronoi
                  diagrams. The concept of medial axis is extended to
                  describe inner and outer medial contours of a
                  polygon. Polygonal regions are decomposed into
                  annular subregions, and path homotopies are
                  introduced to describe the annular subregions. These
                  constructions motivate the definition of a ladder,
                  which guides the construction of grid point pairs
                  necessary to effect the warp itself.},
  keywords =     {computational geometry; image segmentation}
}