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     int ch;
  51
  52
  53     tif = TIFFOpen(file, "r");
  54     if (!tif)
  55       return NULL;
  56
  57     /* seek index */
  58     i = index;
  59     while (i>0) {
  60         if (!TIFFReadDirectory(tif)) {
  61             RErrorCode = RERR_BADINDEX;
  62             TIFFClose(tif);
  63             return NULL;
  64         }
  65         i--;
  66     }
  67
  68     /* get info */
  69     TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width);
  70     TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height);
  71
  72     TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES,
  73                           &extrasamples, &sampleinfo);
  74
  75     alpha = (extrasamples == 1 &&
  76              ((sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA) || (sampleinfo[0] == EXTRASAMPLE_UNASSALPHA)));
  77     amode = (extrasamples == 1 && sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
  78
  79     if (width<1 || height<1) {
  80         RErrorCode = RERR_BADIMAGEFILE;
  81         TIFFClose(tif);
  82         return NULL;
  83     }
  84
  85     /* read data */
  86     ptr = data = (uint32*)_TIFFmalloc(width * height * sizeof(uint32));
  87
  88     if (!data) {
  89         RErrorCode = RERR_NOMEMORY;
  90     } else {
  91         if (!TIFFReadRGBAImage(tif, width, height, data, 0)) {
  92             RErrorCode = RERR_BADIMAGEFILE;
  93         } else {
  94
  95             /* convert data */
  96             image = RCreateImage(width, height, alpha);
  97
  98             if (alpha)
  99                 ch = 4;
 100             else
 101                 ch = 3;
 102
 103             if (image) {
 104                 int x, y;
 105
 106                 r = image->data;
 107                 g = image->data+1;
 108                 b = image->data+2;
 109                 a = image->data+3;
 110
 111                 /* data seems to be stored upside down */
 112                 data += width * (height-1);
 113                 for (y=0; y<height; y++) {
 114                     for (x=0; x<width; x++) {
 115
 116                         *(r) = (*data) & 0xff;
 117                         *(g) = (*data >> 8) & 0xff;
 118                         *(b) = (*data >> 16) & 0xff;
 119
 120                         if (alpha) {
 121                             *(a) = (*data >> 24) & 0xff;
 122
 123                             if (amode && (*a > 0)) {
 124                                 *r = (*r * 255) / *(a);
 125                                 *g = (*g * 255) / *(a);
 126                                 *b = (*b * 255) / *(a);
 127                             }
 128
 129                             a+=4;
 130                         }
 131
 132                         r+=ch; g+=ch; b+=ch;
 133                         data++;
 134                     }
 135                     data -= 2*width;
 136                 }
 137             }
 138         }
 139         _TIFFfree(ptr);
 140     }
 141
 142     TIFFClose(tif);
 143
 144     return image;
 145 }
 146
 147 #endif /* USE_TIFF */