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Fixed loading greyscale with alpha TIFF images.

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The alpha channel was not detected because of wrong hasAlpha determination. Also TIFFReadRGBAImage[Oriented] doesn't appear to decode an alpha channel for images that are greyscale so decode greyscale with alpha images using TIFFReadScanline.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@68947 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Dimitri Schoolwerth 2011-08-28 23:45:17 +00:00
parent a000de7794
commit ebbaec82fa
1 changed files with 48 additions and 20 deletions
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68
src/common/imagtiff.cpp
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@ -330,19 +330,24 @@ bool wxTIFFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
TIFFGetField( tif, TIFFTAG_IMAGEWIDTH, &w );
TIFFGetField( tif, TIFFTAG_IMAGELENGTH, &h );
uint16 photometric;
uint16 samplesPerPixel;
uint16 samplesPerPixel = 0;
(void) TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &samplesPerPixel);
uint16 bitsPerSample = 0;
(void) TIFFGetFieldDefaulted(tif, TIFFTAG_BITSPERSAMPLE, &bitsPerSample);
uint16 extraSamples;
uint16* samplesInfo;
TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &samplesPerPixel);
TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
&extraSamples, &samplesInfo);
uint16 photometric;
if (!TIFFGetField(tif, TIFFTAG_PHOTOMETRIC, &photometric))
{
photometric = PHOTOMETRIC_MINISWHITE;
}
const bool hasAlpha = (extraSamples >= 1
&& ((samplesInfo[0] == EXTRASAMPLE_UNSPECIFIED && samplesPerPixel > 3)
&& ((samplesInfo[0] == EXTRASAMPLE_UNSPECIFIED)
|| samplesInfo[0] == EXTRASAMPLE_ASSOCALPHA
|| samplesInfo[0] == EXTRASAMPLE_UNASSALPHA))
|| (extraSamples == 0 && samplesPerPixel == 4
@ -399,13 +404,22 @@ bool wxTIFFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
bool ok = true;
char msg[1024] = "";
if ( !TIFFRGBAImageOK(tif, msg)
&& planarConfig == PLANARCONFIG_CONTIG
&& samplesPerPixel == 2 && extraSamples == 1)
if
(
(planarConfig == PLANARCONFIG_CONTIG && samplesPerPixel == 2
&& extraSamples == 1)
&&
(
( !TIFFRGBAImageOK(tif, msg) )
|| (bitsPerSample == 8)
)
)
{
const bool isGreyScale = (bitsPerSample == 8);
unsigned char *buf = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(tif));
uint32 pos = 0;
const int minValue = (photometric == PHOTOMETRIC_MINISWHITE) ? 255 : 0;
const bool minIsWhite = (photometric == PHOTOMETRIC_MINISWHITE);
const int minValue = minIsWhite ? 255 : 0;
const int maxValue = 255 - minValue;
/*
@ -421,14 +435,28 @@ bool wxTIFFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
break;
}
for (uint32 x = 0; x < w; ++x)
if (isGreyScale)
{
int mask = buf[x*2/8] << ((x*2)%8);
for (uint32 x = 0; x < w; ++x)
{
uint8 val = minIsWhite ? 255 - buf[x*2] : buf[x*2];
uint8 alpha = minIsWhite ? 255 - buf[x*2+1] : buf[x*2+1];
raster[pos] = val + (val << 8) + (val << 16)
+ (alpha << 24);
pos++;
}
}
else
{
for (uint32 x = 0; x < w; ++x)
{
int mask = buf[x*2/8] << ((x*2)%8);
uint8 val = mask & 128 ? maxValue : minValue;
raster[pos] = val + (val << 8) + (val << 16)
+ ((mask & 64 ? maxValue : minValue) << 24);
pos++;
uint8 val = mask & 128 ? maxValue : minValue;
raster[pos] = val + (val << 8) + (val << 16)
+ ((mask & 64 ? maxValue : minValue) << 24);
pos++;
}
}
}
@ -478,19 +506,19 @@ bool wxTIFFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
image->SetOption(wxIMAGE_OPTION_TIFF_PHOTOMETRIC, photometric);
uint16 spp, bps, compression;
uint16 compression;
/*
Read some baseline TIFF tags which helps when re-saving a TIFF
Copy some baseline TIFF tags which helps when re-saving a TIFF
to be similar to the original image.
*/
if ( TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &spp) )
if (samplesPerPixel)
{
image->SetOption(wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL, spp);
image->SetOption(wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL, samplesPerPixel);
}
if ( TIFFGetFieldDefaulted(tif, TIFFTAG_BITSPERSAMPLE, &bps) )
if (bitsPerSample)
{
image->SetOption(wxIMAGE_OPTION_TIFF_BITSPERSAMPLE, bps);
image->SetOption(wxIMAGE_OPTION_TIFF_BITSPERSAMPLE, bitsPerSample);
}
if ( TIFFGetFieldDefaulted(tif, TIFFTAG_COMPRESSION, &compression) )