TIFFGetField( tif, TIFFTAG_IMAGEWIDTH, &w );
TIFFGetField( tif, TIFFTAG_IMAGELENGTH, &h );
+ uint16 photometric;
+ uint16 samplesPerPixel;
uint16 extraSamples;
uint16* samplesInfo;
+ TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &samplesPerPixel);
TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
&extraSamples, &samplesInfo);
- const bool hasAlpha = (extraSamples == 1 &&
- (samplesInfo[0] == EXTRASAMPLE_ASSOCALPHA ||
- samplesInfo[0] == EXTRASAMPLE_UNASSALPHA));
+ if (!TIFFGetField(tif, TIFFTAG_PHOTOMETRIC, &photometric))
+ {
+ photometric = PHOTOMETRIC_MINISWHITE;
+ }
+ const bool hasAlpha = (extraSamples >= 1
+ && ((samplesInfo[0] == EXTRASAMPLE_UNSPECIFIED && samplesPerPixel > 3)
+ || samplesInfo[0] == EXTRASAMPLE_ASSOCALPHA
+ || samplesInfo[0] == EXTRASAMPLE_UNASSALPHA))
+ || (extraSamples == 0 && samplesPerPixel == 4
+ && photometric == PHOTOMETRIC_RGB);
// guard against integer overflow during multiplication which could result
// in allocating a too small buffer and then overflowing it
}
image->Create( (int)w, (int)h );
- if (!image->Ok())
+ if (!image->IsOk())
{
if (verbose)
{
alpha -= 2*w;
}
- // set the image resolution if it's available
+
+ uint16 spp, bpp, compression;
+ /*
+ Read some baseline TIFF tags which helps when re-saving a TIFF
+ to be similar to the original image.
+ */
+ if ( TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &spp) )
+ {
+ image->SetOption(wxIMAGE_OPTION_SAMPLESPERPIXEL, spp);
+ }
+
+ if ( TIFFGetFieldDefaulted(tif, TIFFTAG_BITSPERSAMPLE, &bpp) )
+ {
+ image->SetOption(wxIMAGE_OPTION_BITSPERSAMPLE, bpp);
+ }
+
+ if ( TIFFGetFieldDefaulted(tif, TIFFTAG_COMPRESSION, &compression) )
+ {
+ image->SetOption(wxIMAGE_OPTION_COMPRESSION, compression);
+ }
+
+ // Set the resolution unit.
+ wxImageResolution resUnit = wxIMAGE_RESOLUTION_NONE;
uint16 tiffRes;
- if ( TIFFGetField(tif, TIFFTAG_RESOLUTIONUNIT, &tiffRes) )
+ if ( TIFFGetFieldDefaulted(tif, TIFFTAG_RESOLUTIONUNIT, &tiffRes) )
{
- wxImageResolution res;
- switch ( tiffRes )
+ switch (tiffRes)
{
default:
wxLogWarning(_("Unknown TIFF resolution unit %d ignored"),
- tiffRes);
+ tiffRes);
// fall through
case RESUNIT_NONE:
- res = wxIMAGE_RESOLUTION_NONE;
+ resUnit = wxIMAGE_RESOLUTION_NONE;
break;
case RESUNIT_INCH:
- res = wxIMAGE_RESOLUTION_INCHES;
+ resUnit = wxIMAGE_RESOLUTION_INCHES;
break;
case RESUNIT_CENTIMETER:
- res = wxIMAGE_RESOLUTION_CM;
+ resUnit = wxIMAGE_RESOLUTION_CM;
break;
}
+ }
- if ( res != wxIMAGE_RESOLUTION_NONE )
- {
- float xres, yres;
- if ( TIFFGetField(tif, TIFFTAG_XRESOLUTION, &xres) )
- image->SetOption(wxIMAGE_OPTION_RESOLUTIONX, wxRound(xres));
+ image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, resUnit);
- if ( TIFFGetField(tif, TIFFTAG_YRESOLUTION, &yres) )
- image->SetOption(wxIMAGE_OPTION_RESOLUTIONY, wxRound(yres));
- }
+ /*
+ Set the image resolution if it's available. Resolution tag is not
+ dependant on RESOLUTIONUNIT != RESUNIT_NONE (according to TIFF spec).
+ */
+ float resX, resY;
+
+ if ( TIFFGetField(tif, TIFFTAG_XRESOLUTION, &resX) )
+ {
+ /*
+ Use a string value to not lose precision.
+ rounding to int as cm and then converting to inch may
+ result in whole integer rounding error, eg. 201 instead of 200 dpi.
+ If an app wants an int, GetOptionInt will convert and round down.
+ */
+ image->SetOption(wxIMAGE_OPTION_RESOLUTIONX,
+ wxString::FromCDouble((double) resX));
}
+ if ( TIFFGetField(tif, TIFFTAG_YRESOLUTION, &resY) )
+ {
+ image->SetOption(wxIMAGE_OPTION_RESOLUTIONY,
+ wxString::FromCDouble((double) resY));
+ }
_TIFFfree( raster );
micro;
const wxString ver(::TIFFGetVersion());
- if ( wxSscanf(ver, "LIBTIFF, Version %d.%d.%d", &major, µ, µ) != 3 )
+ if ( wxSscanf(ver, "LIBTIFF, Version %d.%d.%d", &major, &minor, µ) != 3 )
{
wxLogDebug("Unrecognized libtiff version string \"%s\"", ver);