src/common/imagtiff.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/imagtiff.cpp
   3 // Purpose:     wxImage TIFF handler
   4 // Author:      Robert Roebling
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Robert Roebling
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 // ============================================================================
  11 // declarations
  12 // ============================================================================
  13
  14 // ----------------------------------------------------------------------------
  15 // headers
  16 // ----------------------------------------------------------------------------
  17
  18 // For compilers that support precompilation, includes "wx.h".
  19 #include "wx/wxprec.h"
  20
  21 #ifdef __BORLANDC__
  22     #pragma hdrstop
  23 #endif
  24
  25 #if wxUSE_IMAGE && wxUSE_LIBTIFF
  26
  27 #include "wx/imagtiff.h"
  28 #include "wx/versioninfo.h"
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/log.h"
  32     #include "wx/app.h"
  33     #include "wx/intl.h"
  34     #include "wx/bitmap.h"
  35     #include "wx/module.h"
  36     #include "wx/wxcrtvararg.h"
  37 #endif
  38
  39 extern "C"
  40 {
  41 #ifdef __DMC__
  42     #include "tif_config.h"
  43 #endif
  44     #include "tiff.h"
  45     #include "tiffio.h"
  46 }
  47 #include "wx/filefn.h"
  48 #include "wx/wfstream.h"
  49
  50 #ifndef TIFFLINKAGEMODE
  51     #if defined(__WATCOMC__) && defined(__WXMGL__)
  52         #define TIFFLINKAGEMODE cdecl
  53     #else
  54         #define TIFFLINKAGEMODE LINKAGEMODE
  55     #endif
  56 #endif
  57
  58 // ============================================================================
  59 // implementation
  60 // ============================================================================
  61
  62 // ----------------------------------------------------------------------------
  63 // TIFF library error/warning handlers
  64 // ----------------------------------------------------------------------------
  65
  66 static wxString
  67 FormatTiffMessage(const char *module, const char *fmt, va_list ap)
  68 {
  69     char buf[512];
  70     if ( wxCRT_VsnprintfA(buf, WXSIZEOF(buf), fmt, ap) <= 0 )
  71     {
  72         // this isn't supposed to happen, but if it does, it's better
  73         // than nothing
  74         strcpy(buf, "Incorrectly formatted TIFF message");
  75     }
  76     buf[WXSIZEOF(buf)-1] = 0; // make sure it is always NULL-terminated
  77
  78     wxString msg(buf);
  79     if ( module )
  80         msg += wxString::Format(_(" (in module \"%s\")"), module);
  81
  82     return msg;
  83 }
  84
  85 extern "C"
  86 {
  87
  88 static void
  89 TIFFwxWarningHandler(const char* module, const char *fmt, va_list ap)
  90 {
  91     wxLogWarning("%s", FormatTiffMessage(module, fmt, ap));
  92 }
  93
  94 static void
  95 TIFFwxErrorHandler(const char* module, const char *fmt, va_list ap)
  96 {
  97     wxLogError("%s", FormatTiffMessage(module, fmt, ap));
  98 }
  99
 100 } // extern "C"
 101
 102 //-----------------------------------------------------------------------------
 103 // wxTIFFHandler
 104 //-----------------------------------------------------------------------------
 105
 106 IMPLEMENT_DYNAMIC_CLASS(wxTIFFHandler,wxImageHandler)
 107
 108 wxTIFFHandler::wxTIFFHandler()
 109 {
 110     m_name = wxT("TIFF file");
 111     m_extension = wxT("tif");
 112     m_altExtensions.Add(wxT("tiff"));
 113     m_type = wxBITMAP_TYPE_TIF;
 114     m_mime = wxT("image/tiff");
 115     TIFFSetWarningHandler((TIFFErrorHandler) TIFFwxWarningHandler);
 116     TIFFSetErrorHandler((TIFFErrorHandler) TIFFwxErrorHandler);
 117 }
 118
 119 #if wxUSE_STREAMS
 120
 121 // helper to translate our, possibly 64 bit, wxFileOffset to TIFF, always 32
 122 // bit, toff_t
 123 static toff_t wxFileOffsetToTIFF(wxFileOffset ofs)
 124 {
 125     if ( ofs == wxInvalidOffset )
 126         return (toff_t)-1;
 127
 128     toff_t tofs = wx_truncate_cast(toff_t, ofs);
 129     wxCHECK_MSG( (wxFileOffset)tofs == ofs, (toff_t)-1,
 130                     wxT("TIFF library doesn't support large files") );
 131
 132     return tofs;
 133 }
 134
 135 // another helper to convert standard seek mode to our
 136 static wxSeekMode wxSeekModeFromTIFF(int whence)
 137 {
 138     switch ( whence )
 139     {
 140         case SEEK_SET:
 141             return wxFromStart;
 142
 143         case SEEK_CUR:
 144             return wxFromCurrent;
 145
 146         case SEEK_END:
 147             return wxFromEnd;
 148
 149         default:
 150             return wxFromCurrent;
 151     }
 152 }
 153
 154 extern "C"
 155 {
 156
 157 tsize_t TIFFLINKAGEMODE
 158 wxTIFFNullProc(thandle_t WXUNUSED(handle),
 159           tdata_t WXUNUSED(buf),
 160           tsize_t WXUNUSED(size))
 161 {
 162     return (tsize_t) -1;
 163 }
 164
 165 tsize_t TIFFLINKAGEMODE
 166 wxTIFFReadProc(thandle_t handle, tdata_t buf, tsize_t size)
 167 {
 168     wxInputStream *stream = (wxInputStream*) handle;
 169     stream->Read( (void*) buf, (size_t) size );
 170     return wx_truncate_cast(tsize_t, stream->LastRead());
 171 }
 172
 173 tsize_t TIFFLINKAGEMODE
 174 wxTIFFWriteProc(thandle_t handle, tdata_t buf, tsize_t size)
 175 {
 176     wxOutputStream *stream = (wxOutputStream*) handle;
 177     stream->Write( (void*) buf, (size_t) size );
 178     return wx_truncate_cast(tsize_t, stream->LastWrite());
 179 }
 180
 181 toff_t TIFFLINKAGEMODE
 182 wxTIFFSeekIProc(thandle_t handle, toff_t off, int whence)
 183 {
 184     wxInputStream *stream = (wxInputStream*) handle;
 185
 186     return wxFileOffsetToTIFF(stream->SeekI((wxFileOffset)off,
 187                                             wxSeekModeFromTIFF(whence)));
 188 }
 189
 190 toff_t TIFFLINKAGEMODE
 191 wxTIFFSeekOProc(thandle_t handle, toff_t off, int whence)
 192 {
 193     wxOutputStream *stream = (wxOutputStream*) handle;
 194
 195     return wxFileOffsetToTIFF(stream->SeekO((wxFileOffset)off,
 196                                             wxSeekModeFromTIFF(whence)));
 197 }
 198
 199 int TIFFLINKAGEMODE
 200 wxTIFFCloseIProc(thandle_t WXUNUSED(handle))
 201 {
 202     // there is no need to close the input stream
 203     return 0;
 204 }
 205
 206 int TIFFLINKAGEMODE
 207 wxTIFFCloseOProc(thandle_t handle)
 208 {
 209     wxOutputStream *stream = (wxOutputStream*) handle;
 210
 211     return stream->Close() ? 0 : -1;
 212 }
 213
 214 toff_t TIFFLINKAGEMODE
 215 wxTIFFSizeProc(thandle_t handle)
 216 {
 217     wxStreamBase *stream = (wxStreamBase*) handle;
 218     return (toff_t) stream->GetSize();
 219 }
 220
 221 int TIFFLINKAGEMODE
 222 wxTIFFMapProc(thandle_t WXUNUSED(handle),
 223              tdata_t* WXUNUSED(pbase),
 224              toff_t* WXUNUSED(psize))
 225 {
 226     return 0;
 227 }
 228
 229 void TIFFLINKAGEMODE
 230 wxTIFFUnmapProc(thandle_t WXUNUSED(handle),
 231                tdata_t WXUNUSED(base),
 232                toff_t WXUNUSED(size))
 233 {
 234 }
 235
 236 } // extern "C"
 237
 238 TIFF*
 239 TIFFwxOpen(wxInputStream &stream, const char* name, const char* mode)
 240 {
 241     TIFF* tif = TIFFClientOpen(name, mode,
 242         (thandle_t) &stream,
 243         wxTIFFReadProc, wxTIFFNullProc,
 244         wxTIFFSeekIProc, wxTIFFCloseIProc, wxTIFFSizeProc,
 245         wxTIFFMapProc, wxTIFFUnmapProc);
 246
 247     return tif;
 248 }
 249
 250 TIFF*
 251 TIFFwxOpen(wxOutputStream &stream, const char* name, const char* mode)
 252 {
 253     TIFF* tif = TIFFClientOpen(name, mode,
 254         (thandle_t) &stream,
 255         wxTIFFNullProc, wxTIFFWriteProc,
 256         wxTIFFSeekOProc, wxTIFFCloseOProc, wxTIFFSizeProc,
 257         wxTIFFMapProc, wxTIFFUnmapProc);
 258
 259     return tif;
 260 }
 261
 262 bool wxTIFFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int index )
 263 {
 264     if (index == -1)
 265         index = 0;
 266
 267     image->Destroy();
 268
 269     TIFF *tif = TIFFwxOpen( stream, "image", "r" );
 270
 271     if (!tif)
 272     {
 273         if (verbose)
 274         {
 275             wxLogError( _("TIFF: Error loading image.") );
 276         }
 277
 278         return false;
 279     }
 280
 281     if (!TIFFSetDirectory( tif, (tdir_t)index ))
 282     {
 283         if (verbose)
 284         {
 285             wxLogError( _("Invalid TIFF image index.") );
 286         }
 287
 288         TIFFClose( tif );
 289
 290         return false;
 291     }
 292
 293     uint32 w, h;
 294     uint32 *raster;
 295
 296     TIFFGetField( tif, TIFFTAG_IMAGEWIDTH, &w );
 297     TIFFGetField( tif, TIFFTAG_IMAGELENGTH, &h );
 298
 299     uint16 photometric;
 300     uint16 samplesPerPixel;
 301     uint16 extraSamples;
 302     uint16* samplesInfo;
 303     TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &samplesPerPixel);
 304     TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
 305                           &extraSamples, &samplesInfo);
 306     if (!TIFFGetField(tif, TIFFTAG_PHOTOMETRIC, &photometric))
 307     {
 308         photometric = PHOTOMETRIC_MINISWHITE;
 309     }
 310     const bool hasAlpha = (extraSamples >= 1
 311         && ((samplesInfo[0] == EXTRASAMPLE_UNSPECIFIED && samplesPerPixel > 3)
 312             || samplesInfo[0] == EXTRASAMPLE_ASSOCALPHA
 313             || samplesInfo[0] == EXTRASAMPLE_UNASSALPHA))
 314         || (extraSamples == 0 && samplesPerPixel == 4
 315             && photometric == PHOTOMETRIC_RGB);
 316
 317     // guard against integer overflow during multiplication which could result
 318     // in allocating a too small buffer and then overflowing it
 319     const double bytesNeeded = (double)w * (double)h * sizeof(uint32);
 320     if ( bytesNeeded >= wxUINT32_MAX )
 321     {
 322         if ( verbose )
 323         {
 324             wxLogError( _("TIFF: Image size is abnormally big.") );
 325         }
 326
 327         TIFFClose(tif);
 328
 329         return false;
 330     }
 331
 332     raster = (uint32*) _TIFFmalloc( (uint32)bytesNeeded );
 333
 334     if (!raster)
 335     {
 336         if (verbose)
 337         {
 338             wxLogError( _("TIFF: Couldn't allocate memory.") );
 339         }
 340
 341         TIFFClose( tif );
 342
 343         return false;
 344     }
 345
 346     image->Create( (int)w, (int)h );
 347     if (!image->Ok())
 348     {
 349         if (verbose)
 350         {
 351             wxLogError( _("TIFF: Couldn't allocate memory.") );
 352         }
 353
 354         _TIFFfree( raster );
 355         TIFFClose( tif );
 356
 357         return false;
 358     }
 359
 360     if ( hasAlpha )
 361         image->SetAlpha();
 362
 363     if (!TIFFReadRGBAImage( tif, w, h, raster, 0 ))
 364     {
 365         if (verbose)
 366         {
 367             wxLogError( _("TIFF: Error reading image.") );
 368         }
 369
 370         _TIFFfree( raster );
 371         image->Destroy();
 372         TIFFClose( tif );
 373
 374         return false;
 375     }
 376
 377     unsigned char *ptr = image->GetData();
 378     ptr += w*3*(h-1);
 379
 380     unsigned char *alpha = hasAlpha ? image->GetAlpha() : NULL;
 381     if ( hasAlpha )
 382         alpha += w*(h-1);
 383
 384     uint32 pos = 0;
 385
 386     for (uint32 i = 0; i < h; i++)
 387     {
 388         for (uint32 j = 0; j < w; j++)
 389         {
 390             *(ptr++) = (unsigned char)TIFFGetR(raster[pos]);
 391             *(ptr++) = (unsigned char)TIFFGetG(raster[pos]);
 392             *(ptr++) = (unsigned char)TIFFGetB(raster[pos]);
 393             if ( hasAlpha )
 394                 *(alpha++) = (unsigned char)TIFFGetA(raster[pos]);
 395
 396             pos++;
 397         }
 398
 399         // subtract line we just added plus one line:
 400         ptr -= 2*w*3;
 401         if ( hasAlpha )
 402             alpha -= 2*w;
 403     }
 404
 405
 406     uint16 spp, bpp, compression;
 407     /*
 408     Read some baseline TIFF tags which helps when re-saving a TIFF
 409     to be similar to the original image.
 410     */
 411     if ( TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &spp) )
 412     {
 413         image->SetOption(wxIMAGE_OPTION_SAMPLESPERPIXEL, spp);
 414     }
 415
 416     if ( TIFFGetFieldDefaulted(tif, TIFFTAG_BITSPERSAMPLE, &bpp) )
 417     {
 418         image->SetOption(wxIMAGE_OPTION_BITSPERSAMPLE, bpp);
 419     }
 420
 421     if ( TIFFGetFieldDefaulted(tif, TIFFTAG_COMPRESSION, &compression) )
 422     {
 423         image->SetOption(wxIMAGE_OPTION_COMPRESSION, compression);
 424     }
 425
 426     // Set the resolution unit.
 427     wxImageResolution resUnit = wxIMAGE_RESOLUTION_NONE;
 428     uint16 tiffRes;
 429     if ( TIFFGetFieldDefaulted(tif, TIFFTAG_RESOLUTIONUNIT, &tiffRes) )
 430     {
 431         switch (tiffRes)
 432         {
 433             default:
 434                 wxLogWarning(_("Unknown TIFF resolution unit %d ignored"),
 435                     tiffRes);
 436                 // fall through
 437
 438             case RESUNIT_NONE:
 439                 resUnit = wxIMAGE_RESOLUTION_NONE;
 440                 break;
 441
 442             case RESUNIT_INCH:
 443                 resUnit = wxIMAGE_RESOLUTION_INCHES;
 444                 break;
 445
 446             case RESUNIT_CENTIMETER:
 447                 resUnit = wxIMAGE_RESOLUTION_CM;
 448                 break;
 449         }
 450     }
 451
 452     image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, resUnit);
 453
 454     /*
 455     Set the image resolution if it's available. Resolution tag is not
 456     dependant on RESOLUTIONUNIT != RESUNIT_NONE (according to TIFF spec).
 457     */
 458     float resX, resY;
 459
 460     if ( TIFFGetField(tif, TIFFTAG_XRESOLUTION, &resX) )
 461     {
 462         /*
 463         Use a string value to not lose precision.
 464         rounding to int as cm and then converting to inch may
 465         result in whole integer rounding error, eg. 201 instead of 200 dpi.
 466         If an app wants an int, GetOptionInt will convert and round down.
 467         */
 468         image->SetOption(wxIMAGE_OPTION_RESOLUTIONX,
 469             wxString::FromCDouble((double) resX));
 470     }
 471
 472     if ( TIFFGetField(tif, TIFFTAG_YRESOLUTION, &resY) )
 473     {
 474         image->SetOption(wxIMAGE_OPTION_RESOLUTIONY,
 475             wxString::FromCDouble((double) resY));
 476     }
 477
 478     _TIFFfree( raster );
 479
 480     TIFFClose( tif );
 481
 482     return true;
 483 }
 484
 485 int wxTIFFHandler::DoGetImageCount( wxInputStream& stream )
 486 {
 487     TIFF *tif = TIFFwxOpen( stream, "image", "r" );
 488
 489     if (!tif)
 490         return 0;
 491
 492     int dircount = 0;  // according to the libtiff docs, dircount should be set to 1 here???
 493     do {
 494         dircount++;
 495     } while (TIFFReadDirectory(tif));
 496
 497     TIFFClose( tif );
 498
 499     // NOTE: this function modifies the current stream position but it's ok
 500     //       (see wxImageHandler::GetImageCount)
 501
 502     return dircount;
 503 }
 504
 505 bool wxTIFFHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
 506 {
 507     TIFF *tif = TIFFwxOpen( stream, "image", "w" );
 508
 509     if (!tif)
 510     {
 511         if (verbose)
 512         {
 513             wxLogError( _("TIFF: Error saving image.") );
 514         }
 515
 516         return false;
 517     }
 518
 519     TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
 520     TIFFSetField(tif, TIFFTAG_IMAGEWIDTH,  (uint32)image->GetWidth());
 521     TIFFSetField(tif, TIFFTAG_IMAGELENGTH, (uint32)image->GetHeight());
 522     TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
 523     TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
 524
 525     // save the image resolution if we have it
 526     int xres, yres;
 527     const wxImageResolution res = GetResolutionFromOptions(*image, &xres, &yres);
 528     uint16 tiffRes;
 529     switch ( res )
 530     {
 531         default:
 532             wxFAIL_MSG( wxT("unknown image resolution units") );
 533             // fall through
 534
 535         case wxIMAGE_RESOLUTION_NONE:
 536             tiffRes = RESUNIT_NONE;
 537             break;
 538
 539         case wxIMAGE_RESOLUTION_INCHES:
 540             tiffRes = RESUNIT_INCH;
 541             break;
 542
 543         case wxIMAGE_RESOLUTION_CM:
 544             tiffRes = RESUNIT_CENTIMETER;
 545             break;
 546     }
 547
 548     if ( tiffRes != RESUNIT_NONE )
 549     {
 550         TIFFSetField(tif, TIFFTAG_RESOLUTIONUNIT, tiffRes);
 551         TIFFSetField(tif, TIFFTAG_XRESOLUTION, (float)xres);
 552         TIFFSetField(tif, TIFFTAG_YRESOLUTION, (float)yres);
 553     }
 554
 555
 556     int spp = image->GetOptionInt(wxIMAGE_OPTION_SAMPLESPERPIXEL);
 557     if ( !spp )
 558         spp = 3;
 559
 560     int bpp = image->GetOptionInt(wxIMAGE_OPTION_BITSPERSAMPLE);
 561     if ( !bpp )
 562         bpp = 8;
 563
 564     int compression = image->GetOptionInt(wxIMAGE_OPTION_COMPRESSION);
 565     if ( !compression )
 566     {
 567         // we can't use COMPRESSION_LZW because current version of libtiff
 568         // doesn't implement it ("no longer implemented due to Unisys patent
 569         // enforcement") and other compression methods are lossy so we
 570         // shouldn't use them by default -- and the only remaining one is none
 571         compression = COMPRESSION_NONE;
 572     }
 573
 574     TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, spp);
 575     TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, bpp);
 576     TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, spp*bpp == 1 ? PHOTOMETRIC_MINISBLACK
 577                                                         : PHOTOMETRIC_RGB);
 578     TIFFSetField(tif, TIFFTAG_COMPRESSION, compression);
 579
 580     // scanlinesize if determined by spp and bpp
 581     tsize_t linebytes = (tsize_t)image->GetWidth() * spp * bpp / 8;
 582
 583     if ( (image->GetWidth() % 8 > 0) && (spp * bpp < 8) )
 584         linebytes+=1;
 585
 586     unsigned char *buf;
 587
 588     if (TIFFScanlineSize(tif) > linebytes || (spp * bpp < 24))
 589     {
 590         buf = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(tif));
 591         if (!buf)
 592         {
 593             if (verbose)
 594             {
 595                 wxLogError( _("TIFF: Couldn't allocate memory.") );
 596             }
 597
 598             TIFFClose( tif );
 599
 600             return false;
 601         }
 602     }
 603     else
 604     {
 605         buf = NULL;
 606     }
 607
 608     TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP,TIFFDefaultStripSize(tif, (uint32) -1));
 609
 610     unsigned char *ptr = image->GetData();
 611     for ( int row = 0; row < image->GetHeight(); row++ )
 612     {
 613         if ( buf )
 614         {
 615             if ( spp * bpp > 1 )
 616             {
 617                 // color image
 618                 memcpy(buf, ptr, image->GetWidth());
 619             }
 620             else // black and white image
 621             {
 622                 for ( int column = 0; column < linebytes; column++ )
 623                 {
 624                     uint8 reverse = 0;
 625                     for ( int bp = 0; bp < 8; bp++ )
 626                     {
 627                         if ( ptr[column*24 + bp*3] > 0 )
 628                         {
 629                             // check only red as this is sufficient
 630                             reverse = (uint8)(reverse | 128 >> bp);
 631                         }
 632                     }
 633
 634                     buf[column] = reverse;
 635                 }
 636             }
 637         }
 638
 639         if ( TIFFWriteScanline(tif, buf ? buf : ptr, (uint32)row, 0) < 0 )
 640         {
 641             if (verbose)
 642             {
 643                 wxLogError( _("TIFF: Error writing image.") );
 644             }
 645
 646             TIFFClose( tif );
 647             if (buf)
 648                 _TIFFfree(buf);
 649
 650             return false;
 651         }
 652
 653         ptr += image->GetWidth()*3;
 654     }
 655
 656     (void) TIFFClose(tif);
 657
 658     if (buf)
 659         _TIFFfree(buf);
 660
 661     return true;
 662 }
 663
 664 bool wxTIFFHandler::DoCanRead( wxInputStream& stream )
 665 {
 666     unsigned char hdr[2];
 667
 668     if ( !stream.Read(&hdr[0], WXSIZEOF(hdr)) )     // it's ok to modify the stream position here
 669         return false;
 670
 671     return (hdr[0] == 'I' && hdr[1] == 'I') ||
 672            (hdr[0] == 'M' && hdr[1] == 'M');
 673 }
 674
 675 #endif  // wxUSE_STREAMS
 676
 677 /*static*/ wxVersionInfo wxTIFFHandler::GetLibraryVersionInfo()
 678 {
 679     int major,
 680         minor,
 681         micro;
 682
 683     const wxString ver(::TIFFGetVersion());
 684     if ( wxSscanf(ver, "LIBTIFF, Version %d.%d.%d", &major, &minor, &micro) != 3 )
 685     {
 686         wxLogDebug("Unrecognized libtiff version string \"%s\"", ver);
 687
 688         major =
 689         minor =
 690         micro = 0;
 691     }
 692
 693     wxString copyright;
 694     const wxString desc = ver.BeforeFirst('\n', &copyright);
 695     copyright.Replace("\n", "");
 696
 697     return wxVersionInfo("libtiff", major, minor, micro, desc, copyright);
 698 }
 699
 700 #endif  // wxUSE_LIBTIFF