filter/image-png.c

   1 /*
   2  * "$Id: image-png.c 177 2006-06-21 00:20:03Z jlovell $"
   3  *
   4  *   PNG image routines for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 1993-2006 by Easy Software Products.
   7  *
   8  *   These coded instructions, statements, and computer programs are the
   9  *   property of Easy Software Products and are protected by Federal
  10  *   copyright law.  Distribution and use rights are outlined in the file
  11  *   "LICENSE.txt" which should have been included with this file.  If this
  12  *   file is missing or damaged please contact Easy Software Products
  13  *   at:
  14  *
  15  *       Attn: CUPS Licensing Information
  16  *       Easy Software Products
  17  *       44141 Airport View Drive, Suite 204
  18  *       Hollywood, Maryland 20636 USA
  19  *
  20  *       Voice: (301) 373-9600
  21  *       EMail: cups-info@cups.org
  22  *         WWW: http://www.cups.org
  23  *
  24  *   This file is subject to the Apple OS-Developed Software exception.
  25  *
  26  * Contents:
  27  *
  28  *   _cupsImageReadPNG() - Read a PNG image file.
  29  */
  30
  31 /*
  32  * Include necessary headers...
  33  */
  34
  35 #include "image-private.h"
  36
  37 #if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
  38 #  include <png.h>      /* Portable Network Graphics (PNG) definitions */
  39
  40
  41 /*
  42  * '_cupsImageReadPNG()' - Read a PNG image file.
  43  */
  44
  45 int                                     /* O - Read status */
  46 _cupsImageReadPNG(
  47     cups_image_t    *img,               /* IO - cupsImage */
  48     FILE            *fp,                /* I - cupsImage file */
  49     cups_icspace_t  primary,            /* I - Primary choice for colorspace */
  50     cups_icspace_t  secondary,          /* I - Secondary choice for colorspace */
  51     int             saturation,         /* I - Color saturation (%) */
  52     int             hue,                /* I - Color hue (degrees) */
  53     const cups_ib_t *lut)               /* I - Lookup table for gamma/brightness */
  54 {
  55   int           y;                      /* Looping var */
  56   png_structp   pp;                     /* PNG read pointer */
  57   png_infop     info;                   /* PNG info pointers */
  58   png_uint_32   width,                  /* Width of image */
  59                 height;                 /* Height of image */
  60   int           bit_depth,              /* Bit depth */
  61                 color_type,             /* Color type */
  62                 interlace_type,         /* Interlace type */
  63                 compression_type,       /* Compression type */
  64                 filter_type;            /* Filter type */
  65   png_uint_32   xppm,                   /* X pixels per meter */
  66                 yppm;                   /* Y pixels per meter */
  67   int           bpp;                    /* Bytes per pixel */
  68   int           pass,                   /* Current pass */
  69                 passes;                 /* Number of passes required */
  70   cups_ib_t     *in,                    /* Input pixels */
  71                 *inptr,                 /* Pointer into pixels */
  72                 *out;                   /* Output pixels */
  73   png_color_16  bg;                     /* Background color */
  74
  75
  76  /*
  77   * Setup the PNG data structures...
  78   */
  79
  80   pp   = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  81   info = png_create_info_struct(pp);
  82
  83  /*
  84   * Initialize the PNG read "engine"...
  85   */
  86
  87   png_init_io(pp, fp);
  88
  89  /*
  90   * Get the image dimensions and load the output image...
  91   */
  92
  93   png_read_info(pp, info);
  94
  95   png_get_IHDR(pp, info, &width, &height, &bit_depth, &color_type,
  96                &interlace_type, &compression_type, &filter_type);
  97
  98   fprintf(stderr, "DEBUG: PNG image: %dx%dx%d, color_type=%x (%s%s%s)\n",
  99           (int)width, (int)height, bit_depth, color_type,
 100           (color_type & PNG_COLOR_MASK_COLOR) ? "RGB" : "GRAYSCALE",
 101           (color_type & PNG_COLOR_MASK_ALPHA) ? "+ALPHA" : "",
 102           (color_type & PNG_COLOR_MASK_PALETTE) ? "+PALETTE" : "");
 103
 104   if (color_type & PNG_COLOR_MASK_PALETTE)
 105     png_set_expand(pp);
 106   else if (bit_depth < 8)
 107   {
 108     png_set_packing(pp);
 109     png_set_expand(pp);
 110   }
 111   else if (bit_depth == 16)
 112     png_set_strip_16(pp);
 113
 114   if (color_type & PNG_COLOR_MASK_COLOR)
 115     img->colorspace = (primary == CUPS_IMAGE_RGB_CMYK) ? CUPS_IMAGE_RGB :
 116                                                          primary;
 117   else
 118     img->colorspace = secondary;
 119
 120   if (width == 0 || width > CUPS_IMAGE_MAX_WIDTH ||
 121       height == 0 || height > CUPS_IMAGE_MAX_HEIGHT)
 122   {
 123     fprintf(stderr, "ERROR: PNG image has invalid dimensions %ux%u!\n",
 124             (unsigned)width, (unsigned)height);
 125     fclose(fp);
 126     return (1);
 127   }
 128
 129   img->xsize = width;
 130   img->ysize = height;
 131
 132   if ((xppm = png_get_x_pixels_per_meter(pp, info)) != 0 &&
 133       (yppm = png_get_y_pixels_per_meter(pp, info)) != 0)
 134   {
 135     img->xppi = (int)((float)xppm * 0.0254);
 136     img->yppi = (int)((float)yppm * 0.0254);
 137
 138     if (img->xppi == 0 || img->yppi == 0)
 139     {
 140       fprintf(stderr, "ERROR: PNG image has invalid resolution %dx%d PPI\n",
 141               img->xppi, img->yppi);
 142
 143       img->xppi = img->yppi = 128;
 144     }
 145   }
 146
 147   cupsImageSetMaxTiles(img, 0);
 148
 149   passes = png_set_interlace_handling(pp);
 150
 151  /*
 152   * Handle transparency...
 153   */
 154
 155   if (png_get_valid(pp, info, PNG_INFO_tRNS))
 156     png_set_tRNS_to_alpha(pp);
 157
 158   bg.red   = 65535;
 159   bg.green = 65535;
 160   bg.blue  = 65535;
 161
 162   png_set_background(pp, &bg, PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 163
 164   if (passes == 1)
 165   {
 166    /*
 167     * Load one row at a time...
 168     */
 169
 170     if (color_type == PNG_COLOR_TYPE_GRAY ||
 171         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 172       in = malloc(img->xsize);
 173     else
 174       in = malloc(img->xsize * 3);
 175   }
 176   else
 177   {
 178    /*
 179     * Interlaced images must be loaded all at once...
 180     */
 181
 182     if (color_type == PNG_COLOR_TYPE_GRAY ||
 183         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 184       in = malloc(img->xsize * img->ysize);
 185     else
 186       in = malloc(img->xsize * img->ysize * 3);
 187   }
 188
 189   bpp = cupsImageGetDepth(img);
 190   out = malloc(img->xsize * bpp);
 191
 192  /*
 193   * Read the image, interlacing as needed...
 194   */
 195
 196   for (pass = 1; pass <= passes; pass ++)
 197     for (inptr = in, y = 0; y < img->ysize; y ++)
 198     {
 199       png_read_row(pp, (png_bytep)inptr, NULL);
 200
 201       if (pass == passes)
 202       {
 203        /*
 204         * Output this row...
 205         */
 206
 207         if (color_type & PNG_COLOR_MASK_COLOR)
 208         {
 209           if ((saturation != 100 || hue != 0) && bpp > 1)
 210             cupsImageRGBAdjust(inptr, img->xsize, saturation, hue);
 211
 212           switch (img->colorspace)
 213           {
 214             case CUPS_IMAGE_WHITE :
 215                 cupsImageRGBToWhite(inptr, out, img->xsize);
 216                 break;
 217             case CUPS_IMAGE_RGB :
 218             case CUPS_IMAGE_RGB_CMYK :
 219                 cupsImageRGBToRGB(inptr, out, img->xsize);
 220                 break;
 221             case CUPS_IMAGE_BLACK :
 222                 cupsImageRGBToBlack(inptr, out, img->xsize);
 223                 break;
 224             case CUPS_IMAGE_CMY :
 225                 cupsImageRGBToCMY(inptr, out, img->xsize);
 226                 break;
 227             case CUPS_IMAGE_CMYK :
 228                 cupsImageRGBToCMYK(inptr, out, img->xsize);
 229                 break;
 230           }
 231         }
 232         else
 233         {
 234           switch (img->colorspace)
 235           {
 236             case CUPS_IMAGE_WHITE :
 237                 memcpy(out, inptr, img->xsize);
 238                 break;
 239             case CUPS_IMAGE_RGB :
 240             case CUPS_IMAGE_RGB_CMYK :
 241                 cupsImageWhiteToRGB(inptr, out, img->xsize);
 242                 break;
 243             case CUPS_IMAGE_BLACK :
 244                 cupsImageWhiteToBlack(inptr, out, img->xsize);
 245                 break;
 246             case CUPS_IMAGE_CMY :
 247                 cupsImageWhiteToCMY(inptr, out, img->xsize);
 248                 break;
 249             case CUPS_IMAGE_CMYK :
 250                 cupsImageWhiteToCMYK(inptr, out, img->xsize);
 251                 break;
 252           }
 253         }
 254
 255         if (lut)
 256           cupsImageLut(out, img->xsize * bpp, lut);
 257
 258         _cupsImagePutRow(img, 0, y, img->xsize, out);
 259       }
 260
 261       if (passes > 1)
 262       {
 263         if (color_type & PNG_COLOR_MASK_COLOR)
 264           inptr += img->xsize * 3;
 265         else
 266           inptr += img->xsize;
 267       }
 268     }
 269
 270   png_read_end(pp, info);
 271   png_destroy_read_struct(&pp, &info, NULL);
 272
 273   fclose(fp);
 274   free(in);
 275   free(out);
 276
 277   return (0);
 278 }
 279 #endif /* HAVE_LIBPNG && HAVE_LIBZ */
 280
 281
 282 /*
 283  * End of "$Id: image-png.c 177 2006-06-21 00:20:03Z jlovell $".
 284  */