wrlib/tiff.c

   1 /* tiff.c - load TIFF image from file
   2  *
   3  *  Raster graphics library
   4  *
   5  *  Copyright (c) 1997 Alfredo K. Kojima
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Library General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 2 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Library General Public
  18  *  License along with this library; if not, write to the Free
  19  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <config.h>
  23
  24
  25 #ifdef USE_TIFF
  26
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #include <tiff.h>
  32 #include <tiffio.h>
  33
  34
  35 #include "wraster.h"
  36
  37
  38 RImage*
  39 RLoadTIFF(RContext *context, char *file, int index)
  40 {
  41     RImage *image = NULL;
  42     TIFF *tif;
  43     int i;
  44     unsigned char *r, *g, *b, *a;
  45     uint16 alpha, amode;
  46     uint32 width, height;
  47     uint32 *data, *ptr;
  48     uint16 extrasamples;
  49     uint16 *sampleinfo;
  50
  51
  52     tif = TIFFOpen(file, "r");
  53     if (!tif)
  54       return NULL;
  55
  56     /* seek index */
  57     i = index;
  58     while (i>0) {
  59         if (!TIFFReadDirectory(tif)) {
  60             sprintf(RErrorString, "bad index %i for file \"%s\"", index, file);
  61             TIFFClose(tif);
  62             return NULL;
  63         }
  64         i--;
  65     }
  66
  67     /* get info */
  68     TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width);
  69     TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height);
  70
  71     TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
  72                           &extrasamples, &sampleinfo);
  73
  74     alpha = (extrasamples == 1 &&
  75              ((sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA) || (sampleinfo[0] == EXTRASAMPLE_UNASSALPHA)));
  76     amode = (extrasamples == 1 && sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
  77
  78     if (width<1 || height<1) {
  79         sprintf(RErrorString, "bad data in file \"%s\"", file);
  80         TIFFClose(tif);
  81         return NULL;
  82     }
  83
  84     /* read data */
  85     ptr = data = (uint32*)_TIFFmalloc(width * height * sizeof(uint32));
  86
  87     if (!data) {
  88         sprintf(RErrorString, "out of memory");
  89     } else {
  90         if (!TIFFReadRGBAImage(tif, width, height, data, 0)) {
  91             sprintf(RErrorString, "error reading file \"%s\"", file);
  92         } else {
  93
  94             /* convert data */
  95             image = RCreateImage(width, height, alpha);
  96
  97             if (image) {
  98                 int x, y;
  99
 100                 r = image->data[0];
 101                 g = image->data[1];
 102                 b = image->data[2];
 103                 a = image->data[3];
 104
 105                 /* data seems to be stored upside down */
 106                 data += width * (height-1);
 107                 for (y=0; y<height; y++) {
 108                     for (x=0; x<width; x++) {
 109
 110                         *(r) = (*data) & 0xff;
 111                         *(g) = (*data >> 8) & 0xff;
 112                         *(b) = (*data >> 16) & 0xff;
 113
 114                         if (alpha) {
 115                             *(a) = (*data >> 24) & 0xff;
 116
 117                          if (amode && (*a > 0)) {
 118                                *r = (*r * 255) / *(a);
 119                                *g = (*g * 255) / *(a);
 120                                *b = (*b * 255) / *(a);
 121                             }
 122
 123                                  a++;
 124                         }
 125
 126                         r++; g++; b++;
 127                         data++;
 128                     }
 129                     data -= 2*width;
 130                 }
 131             }
 132         }
 133         _TIFFfree(ptr);
 134     }
 135
 136     TIFFClose(tif);
 137
 138     return image;
 139 }
 140
 141 #endif /* USE_TIFF */