modules/quality2SE.h

   1 #ifndef QUALITY2SE_HEADER_
   2 #define QUALITY2SE_HEADER_
   3
   4 #include "../interfaces.h"
   5
   6
   7 /// \ingroup modules
   8 /** Standard quality-to-SE module - uses fixed SE for all block sizes */
   9 class MQuality2SE_std: public IQuality2SE {
  10
  11         DECLARE_TypeInfo_noSettings( MQuality2SE_std, "Constant square error"
  12         , "Holds the same <b>square error</b> (SE) for all block sizes" )
  13
  14 public:
  15 /**     \name IQuality2SE interface
  16  *      @{ */
  17         float rangeSE(float quality,int /*pixelCount*/) {
  18                 ASSERT( quality>=0 && quality<=1 );
  19                 float maxSE= 4  //  approximate SE for quality=0
  20                 , doubles= 6;   //< how many times the SE doubles
  21                 return maxSE/exp2(doubles) * ( exp2((1-quality)*doubles) - 1 );
  22         }
  23 ///     @}
  24 };
  25
  26
  27 /// \ingroup modules
  28 /** Alternate quality-to-SE module - uses fixed MSE for all block sizes */
  29 class MQuality2SE_alt: public IQuality2SE {
  30
  31         DECLARE_TypeInfo_noSettings( MQuality2SE_alt, "Constant mean square error"
  32         , "Holds the same <b>mean square error</b> (MSE) for all block sizes" )
  33
  34 public:
  35 /**     \name IQuality2SE interface
  36  *      @{ */
  37         float rangeSE(float quality,int pixelCount) {
  38                 ASSERT( quality>=0 && quality<=1 );
  39                 float maxSE= 4  //  approximate SE for quality=0
  40                 , doubles= 6;   //< how many times the SE doubles
  41                 float sizeQuot= pixelCount/sqr(9.0);
  42                 return maxSE/exp2(doubles) * ( exp2((1-quality)*doubles) - 1 ) * sizeQuot;
  43         }
  44 ///     @}
  45 };
  46
  47
  48 #endif // QUALITY2SE_HEADER_