lib/cpExtensions/Algorithms/RGBToYPbPrFunction.h

   1 // -------------------------------------------------------------------------
   2 // @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
   3 // -------------------------------------------------------------------------
   4
   5 #ifndef __CPEXTENSIONS__ALGORITHMS__RGBTOYPBPRFUNCTION__H__
   6 #define __CPEXTENSIONS__ALGORITHMS__RGBTOYPBPRFUNCTION__H__
   7
   8 #include <cmath>
   9 #include <limits>
  10 #include <vnl/vnl_math.h>
  11 #include <vnl/vnl_matrix.h>
  12
  13 #include <itkRGBPixel.h>
  14 #include <itkMatrix.h>
  15 #include <itkVector.h>
  16
  17 namespace cpExtensions
  18 {
  19   namespace Algorithms
  20   {
  21     /**
  22      */
  23     template< class P >
  24     struct RGBToYPbPrFunction
  25     {
  26       typedef RGBToYPbPrFunction    Self;
  27       typedef P                     TOutPixel;
  28       typedef typename P::ValueType TValue;
  29
  30       template< class Tr, class Tg, class Tb >
  31       P operator()( const Tr& r, const Tg& g, const Tb& b ) const
  32         {
  33           static const double M[] =
  34             {
  35               double(  0.2990 ), double(  0.5870 ), double(  0.1140 ),
  36               double( -0.1687 ), double( -0.3313 ), double(  0.5000 ),
  37               double(  0.5000 ), double( -0.4187 ), double( -0.0813 )
  38             };
  39           static const vnl_matrix< double > vM( M, 3, 3 );
  40           static const itk::Matrix< double, 3, 3 > iM( vM );
  41
  42           itk::Vector< double, 3 > rgb;
  43           rgb[ 0 ] = double( r );
  44           rgb[ 1 ] = double( b );
  45           rgb[ 2 ] = double( g );
  46           rgb = iM * rgb;
  47
  48           P out;
  49           out[ 0 ] = TValue( rgb[ 0 ] );
  50           out[ 1 ] = TValue( rgb[ 1 ] );
  51           out[ 2 ] = TValue( rgb[ 2 ] );
  52           return( out );
  53         }
  54
  55       template< class C >
  56       TOutPixel operator()( const itk::RGBPixel< C >& rgb ) const
  57         {
  58           return(
  59             this->operator()(
  60               rgb.GetRed( ), rgb.GetGreen( ), rgb.GetBlue( )
  61               )
  62             );
  63         }
  64     };
  65
  66   } // ecapseman
  67
  68 } // ecapseman
  69
  70 #endif // __CPEXTENSIONS__ALGORITHMS__RGBTOYPBPRFUNCTION__H__
  71
  72 // eof - $RCSfile$