@TechReport{TR084,
  author =	 "Physics-based {S}egmentation of {C}olour {I}mages in
                  {S}pherical {C}oordinates",
  title =	 "Allan Hanbury",
  institution =	 "PRIP, TU Wien",
  number =	 "PRIP-TR-084",
  year =	 "2003",
  url =		 "https://www.prip.tuwien.ac.at/pripfiles/trs/tr84.pdf",
  abstract =	 " We present image segmentation and highlight
                  detection algorithms based on the dichromatic
                  reflection model. For image segmentation, we use the
                  model prediction that objects of a certain colour
                  produce lines (the matte lines) radiating away from
                  the origin of the RGB colour space. These lines
                  therefore show up as peaks in a 2-dimensional
                  histogram of the angular coordinates of a spherical
                  polar coordinate representation of the RGB space. An
                  algorithm for automatically locating these peaks is
                  suggested. When the matte line locations are known,
                  one can define cylindrical polar coordinate systems
                  having their $z$-axes centred on the matte lines. We
                  suggest a Hough-based algorithm for the detection of
                  highlight lines in 2D-histograms of the $\rho$ and
                  $z$ coordinates of the cylindrical polar coordinate
                  system. Examples of the results of applying these
                  algorithms are given.",
}