wrlib/tiff.c

   1 /* tiff.c - load TIFF image from file
   2  *
   3  * Raster graphics library
   4  *
   5  * Copyright (c) 1997-2003 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 #ifdef USE_TIFF
  25
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include <tiff.h>
  31 #include <tiffio.h>
  32
  33 #include "wraster.h"
  34
  35 RImage *RLoadTIFF(RContext * context, char *file, int index)
  36 {
  37         RImage *image = NULL;
  38         TIFF *tif;
  39         int i;
  40         unsigned char *r, *g, *b, *a;
  41         uint16 alpha, amode;
  42         uint32 width, height;
  43         uint32 *data, *ptr;
  44         uint16 extrasamples;
  45         uint16 *sampleinfo;
  46         int ch;
  47
  48         tif = TIFFOpen(file, "r");
  49         if (!tif)
  50                 return NULL;
  51
  52         /* seek index */
  53         i = index;
  54         while (i > 0) {
  55                 if (!TIFFReadDirectory(tif)) {
  56                         RErrorCode = RERR_BADINDEX;
  57                         TIFFClose(tif);
  58                         return NULL;
  59                 }
  60                 i--;
  61         }
  62
  63         /* get info */
  64         TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width);
  65         TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height);
  66
  67         TIFFGetFieldDefaulted(tif, TIFFTAG_EXTRASAMPLES, &extrasamples, &sampleinfo);
  68
  69         alpha = (extrasamples == 1 &&
  70                  ((sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA) || (sampleinfo[0] == EXTRASAMPLE_UNASSALPHA)));
  71         amode = (extrasamples == 1 && sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
  72
  73         if (width < 1 || height < 1) {
  74                 RErrorCode = RERR_BADIMAGEFILE;
  75                 TIFFClose(tif);
  76                 return NULL;
  77         }
  78
  79         /* read data */
  80         ptr = data = (uint32 *) _TIFFmalloc(width * height * sizeof(uint32));
  81
  82         if (!data) {
  83                 RErrorCode = RERR_NOMEMORY;
  84         } else {
  85                 if (!TIFFReadRGBAImage(tif, width, height, data, 0)) {
  86                         RErrorCode = RERR_BADIMAGEFILE;
  87                 } else {
  88
  89                         /* convert data */
  90                         image = RCreateImage(width, height, alpha);
  91
  92                         if (alpha)
  93                                 ch = 4;
  94                         else
  95                                 ch = 3;
  96
  97                         if (image) {
  98                                 int x, y;
  99
 100                                 r = image->data;
 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 += 4;
 124                                                 }
 125
 126                                                 r += ch;
 127                                                 g += ch;
 128                                                 b += ch;
 129                                                 data++;
 130                                         }
 131                                         data -= 2 * width;
 132                                 }
 133                         }
 134                 }
 135                 _TIFFfree(ptr);
 136         }
 137
 138         TIFFClose(tif);
 139
 140         return image;
 141 }
 142
 143 #endif                          /* USE_TIFF */