bool FileFormatInstance::Extract( FITSKeywordArray& keywords )
{
try
{
keywords.Clear();
if ( (*API->FileFormat->BeginKeywordExtraction)( handle ) == api_false )
return false;
for ( size_type i = 0, count = (*API->FileFormat->GetKeywordCount)( handle ); i < count; ++i )
{
IsoString name, value, comment;
name.Reserve( 96 );
value.Reserve( 96 );
comment.Reserve( 96 );
if ( (*API->FileFormat->GetNextKeyword)( handle,
name.Begin(), value.Begin(), comment.Begin(), 81 ) == api_false )
throw APIFunctionError( "GetNextKeyword" );
name.ResizeToNullTerminated();
value.ResizeToNullTerminated();
comment.ResizeToNullTerminated();
keywords.Add( FITSHeaderKeyword( name, value, comment ) );
}
(*API->FileFormat->EndKeywordExtraction)( handle );
return true;
}
catch ( ... )
{
(*API->FileFormat->EndKeywordExtraction)( handle );
throw;
}
}
static void Apply( GenericImage<P>& img, const View& view, const FluxCalibrationInstance& instance )
{
FITSKeywordArray inputKeywords;
view.Window().GetKeywords( inputKeywords );
if ( KeywordExists( inputKeywords, "FLXMIN" ) ||
KeywordExists( inputKeywords, "FLXRANGE" ) ||
KeywordExists( inputKeywords, "FLX2DN" ) )
{
throw Error( "Already calibrated image" );
}
if ( img.IsColor() )
throw Error( "Can't calibrate a color image" );
float Wc = instance.p_wavelength.GetValue( inputKeywords );
float Tr = Max( 1.0F, instance.p_transmissivity.GetValue( inputKeywords ) );
float Delta = instance.p_filterWidth.GetValue( inputKeywords );
float Ap = instance.p_aperture.GetValue( inputKeywords ) / 10; // mm -> cm
float Cobs = Max( 0.0F, instance.p_centralObstruction.GetValue( inputKeywords ) ) / 10; // mm -> cm
float ExpT = instance.p_exposureTime.GetValue( inputKeywords );
float AtmE = Max( 0.0F, instance.p_atmosphericExtinction.GetValue( inputKeywords ) );
float G = Max( 1.0F, instance.p_sensorGain.GetValue( inputKeywords ) );
float QEff = Max( 1.0F, instance.p_quantumEfficiency.GetValue( inputKeywords ) );
if ( Wc <= 0 )
throw Error( "Invalid filter wavelength" );
if ( Tr <= 0 || Tr > 1 )
throw Error( "Invalid filter transmissivity" );
if ( Delta <= 0 )
throw Error( "Invalid filter width" );
if ( Ap <= 0 )
throw Error( "Invalid aperture" );
if ( Cobs < 0 || Cobs >= Ap )
throw Error( "Invalid central obstruction area" );
if ( ExpT <= 0 )
throw Error( "Invalid exposure time" );
if ( AtmE < 0 || AtmE >= 1 )
throw Error( "Invalid atmospheric extinction" );
if ( G <= 0 )
throw Error( "Invalid sensor gain" );
if ( QEff <= 0 || QEff > 1 )
throw Error( "Invalid quantum efficiency" );
FITSKeywordArray keywords;
float pedestal = 0;
bool foundPedestal = false;
for ( FITSKeywordArray::const_iterator i = inputKeywords.Begin(); i != inputKeywords.End(); ++i )
if ( i->name == "PEDESTAL" )
{
if ( i->value.TryToFloat( pedestal ) )
foundPedestal = true;
pedestal /= 65535; // 2^16-1 maximum value of a 16bit CCD.
}
else
keywords.Add( *i );
if ( foundPedestal )
Console().NoteLn( "<end><cbr><br>* FluxCalibration: PEDESTAL keyword found: " + view.FullId() );
// double F = Wc * inv_ch * (1 - Tr) * Delta * Ap * Cobs * ExpT * AtmE * G * QEff;
double F = Wc * inv_ch * (1 - AtmE) * Delta * ( Const<double>::pi() / 4 * ( Ap*Ap - Cobs*Cobs ) ) * ExpT * Tr * G * QEff;
size_type N = img.NumberOfPixels();
typename P::sample* f = img.PixelData( 0 );
const typename P::sample* fN = f + N;
double flxMin = DBL_MAX;
double flxMax = 0;
for ( ; f < fN; ++f, ++img.Status() )
{
double I; P::FromSample( I, *f );
I = (I - pedestal)/F;
*f = P::ToSample( I );
if ( I < flxMin )
flxMin = I;
if ( I > flxMax )
flxMax = I;
}
img.Rescale();
keywords.Add( FITSHeaderKeyword( "FLXMIN",
IsoString().Format( "%.8e", flxMin ),
"" ) );
keywords.Add( FITSHeaderKeyword( "FLXRANGE",
IsoString().Format( "%.8e", flxMax - flxMin ),
"FLXRANGE*pixel_value + FLXMIN = erg/cm^2/s/nm" ) );
keywords.Add( FITSHeaderKeyword( "FLX2DN",
IsoString().Format( "%.8e", F*65535 ),
"(FLXRANGE*pixel_value + FLXMIN)*FLX2DN = DN" ) );
view.Window().SetKeywords( keywords );
}