#include "VsipTypes.h"

/****************************************************************************
 *
 *  Function    : VsipCumulativeDensityEqualizationInt
 *
 *  Description : Computes the cumulative density equalization of an image
 *
 *  Parameters  : src - input image object
 *                cdf_src - cumulative density function of the histogram
 *                denominator - Value to divide the cumulative density function
 *                in order to obtain the probabilities
 *
 *  Returns     : Equalized image
 *
 *  Note        : Range used is max -min +1 instead of max - min as stated in
 *                the manual
 *
 ****************************************************************************/
$generic

   $VsipCumulativeDensityEqualizationInt = 'VsipCumulativeDensityEqualizationInt24',
         $IOType = 'int32', $HistType = 'uint24';
   $VsipCumulativeDensityEqualizationInt = 'VsipCumulativeDensityEqualizationInt32',
         $IOType = 'int32', $HistType = 'uint32';

$in

$IOType[:,:] $VsipCumulativeDensityEqualizationInt ($IOType src[:,:],
                           $HistType cdf_src[:], $HistType denominator)
{

  // ***** recover the src and cdf_src  sizes *****
  VsipIndexesType rs, VsipIndexesType cs = extents(src);
  VsipIndexesType length = extents(cdf_src);

  // ***** test the sizes of the image and cdf  *****
  assert(((rs > 0) && (cs > 0)),
         "ERROR: Image can not have zero dimension. (",rs,"x",cs,")\n");
  assert((length > 0),
         "ERROR: Cdf can not have zero dimension.\n");
  assert((denominator != 0),
         "ERROR: Cdf can not have zero denominator.\n");

  // ***** Computes the max, min and range  values of the src *****
  $IOType maxval = array_max(src);
  $IOType minval = array_min(src);
  $IOType range  = maxval - minval +1 ;
 

  // ***** Computes the equalization using the cumulative density histogram *****
  $IOType dest[:,:] =
       for elem in src
            { // ***** finds the position of the elem in the cumulative hist *****
            VsipIndexesType p = (elem - minval) * length / range;
            assert(p < length,"ERROR: Index out of bounds. (",p,")\n");
            }
       return(array((cdf_src[p] * range + minval * denominator) / denominator));

} return(dest);

$end_generic
 

/****************************************************************************
 *
 *  Function    : VsipCumulativeDensityEqualizationFloat
 *
 *  Description : Computes the cumulative density equalization of an image
 *
 *  Parameters  : src - input image object
 *                cdf_src - cumulative density function of the histogram
 *                denominator - Value to divide the cumulative density function
 *                n order to obtain the probabilities
 *
 *  Returns     : Equalized image
 *
 ****************************************************************************/
$generic

   $VsipCumulativeDensityEqualizationFloat='VsipCumulativeDensityEqualizationFloat24',
         $IOType = 'float', $HistType = 'uint24';
   $VsipCumulativeDensityEqualizationFloat='VsipCumulativeDensityEqualizationFloat32',
         $IOType = 'float', $HistType = 'uint32';

$in

$IOType[:,:] $VsipCumulativeDensityEqualizationFloat ($IOType src[:,:],
                              $HistType cdf_src[:], $HistType denominator)
{

  // ***** recover the src and cdf_src  sizes *****
  VsipIndexesType rs, VsipIndexesType cs = extents(src);
  VsipIndexesType length = extents(cdf_src);

  // ***** test the sizes of the image and cdf  *****
  assert(((rs > 0) && (cs > 0)),
         "ERROR: Image can not have zero dimension. (",rs,"x",cs,")\n");
  assert((length > 0),
         "ERROR: Cdf can not have zero dimension.\n");
  assert((denominator != 0),
         "ERROR: Cdf can not have zero denominator.\n");

  // ***** Computes the max, min and range  values of the src *****
  $IOType maxval = array_max(src);
  $IOType minval = array_min(src);
  $IOType range  = AuxMax(1, maxval - minval);
 

  // ***** Computes the equalization using the cumulative density histogram *****
  $IOType dest[:,:] =
       for elem in src
            { // ***** finds the position of the elem in the cumulative hist *****
            VsipIndexesType p = (elem - minval) * length / range;
            assert(p < length,"ERROR: Index out of bounds. (",p,")\n");
            }
       return(array((cdf_src[p] * range + minval * denominator) / denominator));

} return(dest);

$end_generic