@TechReport{Zimmermann-TR-2005-23,
  IS = { zkontrolovano 26 Jan 2006 },
  UPDATE  = { 2005-12-15 },
author =       {Zimmermann, Karel and Svoboda, Tom{\'a}{\v s}},
title =        {Approximation of Euclidean Distance between Point
                from Ellipse},
institution =  {Center for Machine Perception, K13133 FEE Czech Technical
                University},
address =      {Prague, Czech Republic},
year =         {2005},
month =        {August},
type =         {Research Report},
number =       {{CTU--CMP--2005--23}},
issn =         {1213-2365},
pages =        {4},
authorship =   {50-50},
annote = {Efficient computation of Euclidean distance between point
  and ellipse is needed in many computer vision problems. The true
  Euclidean distance requires solving of quartic equation which may
  have up to four solutions, requiring the one with the minimum
  distance to be determined. To avoid the complexity of evaluating the
  true Euclidean distance, we propose an approximation measure. We
  first find transformation projecting the ellipse to the unit
  circle. The point is projected by the same transformation. Distance
  of the point from the unit circle is simple to compute. Finally,
  distance is reprojected to original space.},
keywords =     {computer vision, distance approximation},
project =      { 1ET101210407, Dur IG2003-2 062, 
                 CONEX GZ 45.535 },
psurl =         {[PDF] },
}