///////////////////////////////////////////////////////////////////////////////
// Gain function
//
///////////////////////////////////////////////////////////////////////////////
GEM_EXTERN float gainFunc(float x, float a)
{
if (x < 0.5f)
return( biasFunc(2.f * x, 1.f - a) / 2.f);
else
return(1.f - biasFunc(2.f - 2.f*x, 1.f - a) / 2.f);
// return(0.f);
}
void ToneMappingDrago03::calctoneMapping_Drago03CPU()
{
const float LOG05 = -0.693147f; // log(0.5)
// Normal tone mapping of every pixel
int i, j;
for(j = 0; j < image->getHeight(); j++)
for(i = 0; i < image->getWidth(); i++)
{
float Yw = image->getImage()[j * image->getWidth() * 3 + 3 * i + 1] / *avLuminance;
float interpol = log (2.0f + biasFunc(biasP, Yw / normMaxLum) * 8.0f);
float yg = ( log(Yw+1.0f)/interpol ) / divider;
float scale = yg / image->getImage()[j * image->getWidth() * 3 + 3 * i + 1];
picture[j * image->getWidth() * 3 + 3 * i + 0] = (unsigned int)(clampq(image->getImage()[j * image->getWidth() * 3 + 3 * i + 0] * scale, 0.0f, 1.0f) * 255);
picture[j * image->getWidth() * 3 + 3 * i + 1] = (unsigned int)(clampq(image->getImage()[j * image->getWidth() * 3 + 3 * i + 1] * scale, 0.0f, 1.0f) * 255);
picture[j * image->getWidth() * 3 + 3 * i + 2] = (unsigned int)(clampq(image->getImage()[j * image->getWidth() * 3 + 3 * i + 2] * scale, 0.0f, 1.0f) * 255);
}
}
void tmo_drago03(float* Y, float* L, int height, int width, float maxLum, float avLum, float bias)
{
const float LOG05 = -0.693147f; // log(0.5)
//assert(Y!=NULL);
//assert(L!=NULL);
int nrows = height; // image size
int ncols = width;
//assert(nrows==L->getRows() && ncols==L->getCols() );
maxLum /= avLum; // normalize maximum luminance by average luminance
float divider = log10(maxLum+1.0f);
float biasP = log(bias)/LOG05;
#if !FAST
// Normal tone mapping of every pixel
for( int y=0 ; y<nrows; y++)
for( int x=0 ; x<ncols; x++)
{
float Yw = Y[x+y*ncols] / avLum;
float interpol = log (2.0f + biasFunc(biasP, Yw / maxLum) * 8.0f);
L[x+y*ncols] = ( log(Yw+1.0f)/interpol ) / divider;
}
#else
// Approximation of log(x+1)
// x(6+x)/(6+4x) good if x < 1
// x*(6 + 0.7662x)/(5.9897 + 3.7658x) between 1 and 2
// http://users.pandora.be/martin.brown/home/consult/logx.htm
int i,j;
for(int y=0; y<nrows; y+=3)
for(int x=0; x<ncols; x+=3)
{
float average = 0.0f;
for (i=0; i<3; i++)
for (j=0; j<3; j++)
average += Y[x+i + (y+j)*ncols] / avLum;
average = average / 9.0f - Y[x+y*ncols];
if (average>-1.0f && average<1.0f )
{
float interpol = log(2.0f + biasFunc(biasP, Y[x+1 + (y+1)*ncols]/maxLum) * 8.0f);
for (i=0; i<3; i++)
for (j=0; j<3; j++)
{
float Yw = Y[x+i + (y+j)*ncols];
if( Yw<1.0f )
{
float L = Yw*(6.0f+Yw) / (6.0f+4.0f*Yw);
Yw = (L/interpol) / divider;
}
else if( Yw>=1.0f && Yw<2.0f )
{
float L = Yw*(6.0f+0.7662*Yw) / (5.9897f+3.7658f*Yw);
Yw = (L/interpol) / divider;
}
else
Yw = ( log(Yw+1.0f)/interpol ) / divider;
L[x+i + (y+j)*ncols] = Yw;
}
}
else
{
for (i=0; i<3; i++)
for (j=0; j<3; j++)
{
float Yw = Y[x+i + (y+j)*ncols];
float interpol = log(2.0f+biasFunc(biasP, Yw/maxLum)*8.0f);
L[x+i + (y+j)*ncols] = ( log(Yw+1.0f)/interpol ) / divider;
}
}
}
#endif // #else #ifndef FAST
}
void tmo_drago03(unsigned int width, unsigned int height,
const float* _Y, float* _L,
float maxLum, float avLum, float bias)
{
const float LOG05 = -0.693147f; // log(0.5)
assert(_Y!=NULL);
assert(_L!=NULL);
const pfstmo::Array2D* Y = new pfstmo::Array2D(width, height, const_cast<float*>(_Y));
pfstmo::Array2D* L = new pfstmo::Array2D(width, height, _L);
int nrows = Y->getRows(); // image size
int ncols = Y->getCols();
assert(nrows==L->getRows() && ncols==L->getCols() );
maxLum /= avLum; // normalize maximum luminance by average luminance
float divider = log10(maxLum+1.0f);
float biasP = log(bias)/LOG05;
#if !FAST
// Normal tone mapping of every pixel
for( int y=0 ; y<nrows; y++)
for( int x=0 ; x<ncols; x++)
{
float Yw = (*Y)(x,y) / avLum;
float interpol = log (2.0f + biasFunc(biasP, Yw / maxLum) * 8.0f);
(*L)(x,y) = ( log(Yw+1.0f)/interpol ) / divider;
}
#else
// Approximation of log(x+1)
// x(6+x)/(6+4x) good if x < 1
// x*(6 + 0.7662x)/(5.9897 + 3.7658x) between 1 and 2
// http://users.pandora.be/martin.brown/home/consult/logx.htm
int i,j;
for(int y=0; y<nrows; y+=3)
for(int x=0; x<ncols; x+=3)
{
float average = 0.0f;
for (i=0; i<3; i++)
for (j=0; j<3; j++)
average += (*Y)(x+i,y+j) / avLum;
average = average / 9.0f - (*Y)(x,y);
if (average>-1.0f && average<1.0f )
{
float interpol = log(2.0f + biasFunc(biasP, (*Y)(x+1,y+1)/maxLum) * 8.0f);
for (i=0; i<3; i++)
for (j=0; j<3; j++)
{
float Yw = (*Y)(x+i,y+j);
if( Yw<1.0f )
{
float L = Yw*(6.0f+Yw) / (6.0f+4.0f*Yw);
Yw = (L/interpol) / divider;
}
else if( Yw>=1.0f && Yw<2.0f )
{
float L = Yw*(6.0f+0.7662*Yw) / (5.9897f+3.7658f*Yw);
Yw = (L/interpol) / divider;
}
else
Yw = ( log(Yw+1.0f)/interpol ) / divider;
(*L)(x+i,y+j) = Yw;
}
}
else
{
for (i=0; i<3; i++)
for (j=0; j<3; j++)
{
float Yw = (*Y)(x+i,y+j);
float interpol = log(2.0f+biasFunc(biasP, Yw/maxLum)*8.0f);
(*L)(x+i,y+j) = ( log(Yw+1.0f)/interpol ) / divider;
}
}
}
#endif // #else #ifndef FAST
delete L;
delete Y;
}
