lib/cpExtensions/Algorithms/RGBToSingleChannelFunctor.hxx

   1 // -------------------------------------------------------------------------
   2 // @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
   3 // -------------------------------------------------------------------------
   4
   5 #ifndef __cpExtensions__Algorithms__RGBToSingleChannelFunctor__hxx__
   6 #define __cpExtensions__Algorithms__RGBToSingleChannelFunctor__hxx__
   7
   8 #include <cmath>
   9 #include <limits>
  10 #include <vnl/vnl_math.h>
  11
  12 // -------------------------------------------------------------------------
  13 template< class _TScalar >
  14 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  15 IsChannelRed( ) const
  16 {
  17   return( this->m_Channel == Self::Red );
  18 }
  19
  20 // -------------------------------------------------------------------------
  21 template< class _TScalar >
  22 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  23 IsChannelGreen( ) const
  24 {
  25   return( this->m_Channel == Self::Green );
  26 }
  27
  28 // -------------------------------------------------------------------------
  29 template< class _TScalar >
  30 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  31 IsChannelBlue( ) const
  32 {
  33   return( this->m_Channel == Self::Blue );
  34 }
  35
  36 // -------------------------------------------------------------------------
  37 template< class _TScalar >
  38 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  39 IsChannelHue( ) const
  40 {
  41   return( this->m_Channel == Self::Hue );
  42 }
  43
  44 // -------------------------------------------------------------------------
  45 template< class _TScalar >
  46 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  47 IsChannelSaturation( ) const
  48 {
  49   return( this->m_Channel == Self::Saturation );
  50 }
  51
  52 // -------------------------------------------------------------------------
  53 template< class _TScalar >
  54 bool cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  55 IsChannelValue( ) const
  56 {
  57   return( this->m_Channel == Self::Value );
  58 }
  59
  60 // -------------------------------------------------------------------------
  61 template< class _TScalar >
  62 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  63 SetChannelToRed( )
  64 {
  65   this->SetChannel( Self::Red );
  66 }
  67
  68 // -------------------------------------------------------------------------
  69 template< class _TScalar >
  70 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  71 SetChannelToGreen( )
  72 {
  73   this->SetChannel( Self::Green );
  74 }
  75
  76 // -------------------------------------------------------------------------
  77 template< class _TScalar >
  78 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  79 SetChannelToBlue( )
  80 {
  81   this->SetChannel( Self::Blue );
  82 }
  83
  84 // -------------------------------------------------------------------------
  85 template< class _TScalar >
  86 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  87 SetChannelToHue( )
  88 {
  89   this->SetChannel( Self::Hue );
  90 }
  91
  92 // -------------------------------------------------------------------------
  93 template< class _TScalar >
  94 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
  95 SetChannelToSaturation( )
  96 {
  97   this->SetChannel( Self::Saturation );
  98 }
  99
 100 // -------------------------------------------------------------------------
 101 template< class _TScalar >
 102 void cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
 103 SetChannelToValue( )
 104 {
 105   this->SetChannel( Self::Value );
 106 }
 107
 108 // -------------------------------------------------------------------------
 109 template< class _TScalar >
 110 _TScalar cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
 111 Evaluate( const TPixel& pixel ) const
 112 {
 113   _TScalar res;
 114   switch( this->m_Channel )
 115   {
 116   case Self::Hue:
 117   {
 118     double R = double( pixel.GetRed( ) );
 119     double G = double( pixel.GetRed( ) );
 120     double B = double( pixel.GetBlue( ) );
 121     double RG = R - G;
 122     double RB = R - B;
 123     double GB = G - B;
 124     double A = std::sqrt( ( RG * RG ) + ( RB * GB ) );
 125     if( A != _0 )
 126       A = std::acos( ( RG + RB ) / ( double( 2 ) * A ) );
 127     A /= double( 2 ) * double( vnl_math::pi );
 128     res =
 129       _TScalar(
 130         double( std::numeric_limits< _TScalar >::max( ) ) *
 131         ( ( G >= B )? A: double( 1 ) - A )
 132         );
 133   }
 134   break;
 135   case Self::Saturation:
 136   {
 137     double R = double( r );
 138     double G = double( g );
 139     double B = double( b );
 140     double sRGB = R + G + B;
 141     double RG = R - G;
 142     double RB = R - B;
 143     double GB = G - B;
 144     if( sRGB != double( 0 ) )
 145     {
 146       double C = ( G < R )? G: R;
 147       C        = ( B < C )? B: C;
 148       res =
 149         _TScalar(
 150           double( std::numeric_limits< _TScalar >::max( ) ) *
 151           ( double( 1 ) - ( ( double( 3 ) * C ) / sRGB ) )
 152           );
 153     }
 154     else
 155       res = _TScalar( 0 );
 156   }
 157   break;
 158   case Self::Value:
 159   {
 160     res = ( pixel.GetRed( ) + pixel.GetGreen( ) + pixel.GetBlue( ) ) / 3;
 161   }
 162   break;
 163   case Self::Green:        { res = pixel.GetGreen( ); } break;
 164   case Self::Blue:         { res = pixel.GetBlue( );  } break;
 165   case Self::Red: default: { res = pixel.GetRed( );   } break;
 166   } // hctiws
 167   return( res );
 168 }
 169
 170 // -------------------------------------------------------------------------
 171 template< class _TScalar >
 172 cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
 173 RGBToSingleChannelFunctor( )
 174   : Superclass( )
 175 {
 176   this->SetChannelToRed( );
 177 }
 178
 179 // -------------------------------------------------------------------------
 180 template< class _TScalar >
 181 cpExtensions::Algorithms::RGBToSingleChannelFunctor< _TScalar >::
 182 ~RGBToSingleChannelFunctor( )
 183 {
 184 }
 185
 186 #endif // __cpExtensions__Algorithms__RGBToSingleChannelFunctor__hxx__
 187
 188 // eof - $RCSfile$