ENH: Adding Polygon Compacity filter

Code/BasicFilters/otbPolygonCompacityFunctor.h

+/*=========================================================================
+
+Program:   ORFEO Toolbox
+Language:  C++
+Date:      $Date$
+Version:   $Revision$
+
+
+Copyright (c) Centre National d'Etudes Spatiales. All rights reserved.
+See OTBCopyright.txt for details.
+
+
+This software is distributed WITHOUT ANY WARRANTY; without even 
+the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
+PURPOSE.  See the above copyright notices for more information.
+
+=========================================================================*/
+#ifndef __otbPolygonCompacityFunctor_h
+#define __otbPolygonCompacityFunctor_h
+
+#include "otbMath.h"
+
+namespace otb
+{
+
+    /** \class PolygonCompacityFunctor
+     *  \brief 
+     *  \ingroup Functor
+     */
+  template <class TInput1>
+  class PolygonCompacityFunctor
+  {
+    public:
+      PolygonCompacityFunctor() {};
+      ~PolygonCompacityFunctor() {};
+      inline bool operator()(const TInput1 & input)
+      {
+        double circularityRatio = 4*M_PI*input->GetSurface()
+            / M_SQUARE(input->GetLength());
+      
+        if (circularityRatio > 0.2)
+        {
+          return true;
+        }
+        else
+        {
+          return false;
+        }
+      }
+  };
+
+}
+
+#endif