in modules/imgcodecs/src/grfmt_exr.cpp [185:385]
bool ExrDecoder::readData( Mat& img )
{
m_native_depth = CV_MAT_DEPTH(type()) == img.depth();
bool color = img.channels() > 1;
uchar* data = img.ptr();
int step = img.step;
bool justcopy = m_native_depth;
bool chromatorgb = false;
bool rgbtogray = false;
bool result = true;
FrameBuffer frame;
int xsample[3] = {1, 1, 1};
char *buffer;
int xstep;
int ystep;
xstep = m_native_depth ? 4 : 1;
if( !m_native_depth || (!color && m_iscolor ))
{
buffer = (char *)new float[ m_width * 3 ];
ystep = 0;
}
else
{
buffer = (char *)data;
ystep = step;
}
if( m_ischroma )
{
if( color )
{
if( m_iscolor )
{
if( m_blue )
{
frame.insert( "BY", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep,
12, ystep, m_blue->xSampling, m_blue->ySampling, 0.0 ));
xsample[0] = m_blue->ySampling;
}
if( m_green )
{
frame.insert( "Y", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 4,
12, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
xsample[1] = m_green->ySampling;
}
if( m_red )
{
frame.insert( "RY", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 8,
12, ystep, m_red->xSampling, m_red->ySampling, 0.0 ));
xsample[2] = m_red->ySampling;
}
chromatorgb = true;
}
else
{
frame.insert( "Y", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep,
12, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
frame.insert( "Y", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 4,
12, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
frame.insert( "Y", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 8,
12, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
xsample[0] = m_green->ySampling;
xsample[1] = m_green->ySampling;
xsample[2] = m_green->ySampling;
}
}
else
{
frame.insert( "Y", Slice( m_type,
buffer - m_datawindow.min.x * 4 - m_datawindow.min.y * ystep,
4, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
xsample[0] = m_green->ySampling;
}
}
else
{
if( m_blue )
{
frame.insert( "B", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep,
12, ystep, m_blue->xSampling, m_blue->ySampling, 0.0 ));
xsample[0] = m_blue->ySampling;
}
if( m_green )
{
frame.insert( "G", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 4,
12, ystep, m_green->xSampling, m_green->ySampling, 0.0 ));
xsample[1] = m_green->ySampling;
}
if( m_red )
{
frame.insert( "R", Slice( m_type,
buffer - m_datawindow.min.x * 12 - m_datawindow.min.y * ystep + 8,
12, ystep, m_red->xSampling, m_red->ySampling, 0.0 ));
xsample[2] = m_red->ySampling;
}
if(color == 0)
{
rgbtogray = true;
justcopy = false;
}
}
m_file->setFrameBuffer( frame );
if( justcopy )
{
m_file->readPixels( m_datawindow.min.y, m_datawindow.max.y );
if( color )
{
if( m_blue && (m_blue->xSampling != 1 || m_blue->ySampling != 1) )
UpSample( data, 3, step / xstep, xsample[0], m_blue->ySampling );
if( m_green && (m_green->xSampling != 1 || m_green->ySampling != 1) )
UpSample( data + xstep, 3, step / xstep, xsample[1], m_green->ySampling );
if( m_red && (m_red->xSampling != 1 || m_red->ySampling != 1) )
UpSample( data + 2 * xstep, 3, step / xstep, xsample[2], m_red->ySampling );
}
else if( m_green && (m_green->xSampling != 1 || m_green->ySampling != 1) )
UpSample( data, 1, step / xstep, xsample[0], m_green->ySampling );
}
else
{
uchar *out = data;
int x, y;
for( y = m_datawindow.min.y; y <= m_datawindow.max.y; y++ )
{
m_file->readPixels( y, y );
if( rgbtogray )
{
if( xsample[0] != 1 )
UpSampleX( (float *)buffer, 3, xsample[0] );
if( xsample[1] != 1 )
UpSampleX( (float *)buffer + 4, 3, xsample[1] );
if( xsample[2] != 1 )
UpSampleX( (float *)buffer + 8, 3, xsample[2] );
RGBToGray( (float *)buffer, (float *)out );
}
else
{
if( xsample[0] != 1 )
UpSampleX( (float *)buffer, 3, xsample[0] );
if( xsample[1] != 1 )
UpSampleX( (float *)(buffer + 4), 3, xsample[1] );
if( xsample[2] != 1 )
UpSampleX( (float *)(buffer + 8), 3, xsample[2] );
if( chromatorgb )
ChromaToBGR( (float *)buffer, 1, step );
if( m_type == FLOAT )
{
float *fi = (float *)buffer;
for( x = 0; x < m_width * 3; x++)
{
out[x] = cv::saturate_cast<uchar>(fi[x]*5);
}
}
else
{
unsigned *ui = (unsigned *)buffer;
for( x = 0; x < m_width * 3; x++)
{
out[x] = cv::saturate_cast<uchar>(ui[x]);
}
}
}
out += step;
}
if( color )
{
if( m_blue && (m_blue->xSampling != 1 || m_blue->ySampling != 1) )
UpSampleY( data, 3, step / xstep, m_blue->ySampling );
if( m_green && (m_green->xSampling != 1 || m_green->ySampling != 1) )
UpSampleY( data + xstep, 3, step / xstep, m_green->ySampling );
if( m_red && (m_red->xSampling != 1 || m_red->ySampling != 1) )
UpSampleY( data + 2 * xstep, 3, step / xstep, m_red->ySampling );
}
else if( m_green && (m_green->xSampling != 1 || m_green->ySampling != 1) )
UpSampleY( data, 1, step / xstep, m_green->ySampling );
}
if( chromatorgb )
ChromaToBGR( (float *)data, m_height, step / xstep );
close();
return result;
}