+ int compression = image->GetOptionInt(wxIMAGE_OPTION_COMPRESSION);
+ if ( !compression )
+ compression=COMPRESSION_LZW;
+
+ TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, spp);
+ TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, bpp);
+ TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, spp*bpp == 1 ? PHOTOMETRIC_MINISBLACK
+ : PHOTOMETRIC_RGB);
+ TIFFSetField(tif, TIFFTAG_COMPRESSION, compression);
+
+ // scanlinesize if determined by spp and bpp
+ tsize_t linebytes = (tsize_t)image->GetWidth() * spp * bpp / 8;
+
+ if ( (image->GetWidth() % 8 > 0) && (spp * bpp < 8) )
+ linebytes+=1;
+
+ unsigned char *buf;
+
+ if (TIFFScanlineSize(tif) > linebytes || (spp * bpp < 24))
+ {
+ buf = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(tif));
+ if (!buf)
+ {
+ if (verbose)
+ wxLogError( _("TIFF: Couldn't allocate memory.") );
+
+ TIFFClose( tif );
+
+ return false;
+ }
+ }
+ else
+ {
+ buf = NULL;
+ }
+
+ TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP,TIFFDefaultStripSize(tif, (uint32) -1));
+
+ uint8 bitmask;
+
+ unsigned char *ptr = image->GetData();
+ for ( int row = 0; row < image->GetHeight(); row++ )
+ {
+ if ( buf )
+ {
+ if ( spp * bpp > 1 )
+ {
+ // color image
+ memcpy(buf, ptr, image->GetWidth());
+ }
+ else // black and white image
+ {
+ for ( int column = 0; column < linebytes; column++ )
+ {
+ uint8 reverse = 0;
+ bitmask = 1;
+ for ( int bp = 0; bp < 8; bp++ )
+ {
+ if ( ptr[column*24 + bp*3] > 0 )
+ {
+ // check only red as this is sufficient
+ reverse = reverse | 128 >> bp;
+ }
+
+ bitmask <<= 1;
+ }
+
+ buf[column] = reverse;
+ }
+ }
+ }
+
+ if ( TIFFWriteScanline(tif, buf ? buf : ptr, (uint32)row, 0) < 0 )
+ {
+ if (verbose)
+ wxLogError( _("TIFF: Error writing image.") );
+
+ TIFFClose( tif );
+ if (buf)
+ _TIFFfree(buf);
+
+ return false;
+ }
+
+ ptr += image->GetWidth()*3;
+ }
+
+ (void) TIFFClose(tif);
+
+ if (buf)
+ _TIFFfree(buf);
+
+ return true;
+}
+
+bool wxTIFFHandler::DoCanRead( wxInputStream& stream )
+{
+ unsigned char hdr[2];
+
+ if ( !stream.Read(&hdr[0], WXSIZEOF(hdr)) )
+ return false;
+
+ return (hdr[0] == 'I' && hdr[1] == 'I') ||
+ (hdr[0] == 'M' && hdr[1] == 'M');
+}