filter/image-png.c

   1 /*
   2  * "$Id: image-png.c 6649 2007-07-11 21:46:42Z mike $"
   3  *
   4  *   PNG image routines for the Common UNIX Printing System (CUPS).
   5  *
   6  *   Copyright 2007 by Apple Inc.
   7  *   Copyright 1993-2007 by Easy Software Products.
   8  *
   9  *   These coded instructions, statements, and computer programs are the
  10  *   property of Apple Inc. and are protected by Federal copyright
  11  *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
  12  *   which should have been included with this file.  If this file is
  13  *   file is missing or damaged, see the license at "http://www.cups.org/".
  14  *
  15  *   This file is subject to the Apple OS-Developed Software exception.
  16  *
  17  * Contents:
  18  *
  19  *   _cupsImageReadPNG() - Read a PNG image file.
  20  */
  21
  22 /*
  23  * Include necessary headers...
  24  */
  25
  26 #include "image-private.h"
  27
  28 #if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
  29 #  include <png.h>      /* Portable Network Graphics (PNG) definitions */
  30
  31
  32 /*
  33  * '_cupsImageReadPNG()' - Read a PNG image file.
  34  */
  35
  36 int                                     /* O - Read status */
  37 _cupsImageReadPNG(
  38     cups_image_t    *img,               /* IO - cupsImage */
  39     FILE            *fp,                /* I - cupsImage file */
  40     cups_icspace_t  primary,            /* I - Primary choice for colorspace */
  41     cups_icspace_t  secondary,          /* I - Secondary choice for colorspace */
  42     int             saturation,         /* I - Color saturation (%) */
  43     int             hue,                /* I - Color hue (degrees) */
  44     const cups_ib_t *lut)               /* I - Lookup table for gamma/brightness */
  45 {
  46   int           y;                      /* Looping var */
  47   png_structp   pp;                     /* PNG read pointer */
  48   png_infop     info;                   /* PNG info pointers */
  49   png_uint_32   width,                  /* Width of image */
  50                 height;                 /* Height of image */
  51   int           bit_depth,              /* Bit depth */
  52                 color_type,             /* Color type */
  53                 interlace_type,         /* Interlace type */
  54                 compression_type,       /* Compression type */
  55                 filter_type;            /* Filter type */
  56   png_uint_32   xppm,                   /* X pixels per meter */
  57                 yppm;                   /* Y pixels per meter */
  58   int           bpp;                    /* Bytes per pixel */
  59   int           pass,                   /* Current pass */
  60                 passes;                 /* Number of passes required */
  61   cups_ib_t     *in,                    /* Input pixels */
  62                 *inptr,                 /* Pointer into pixels */
  63                 *out;                   /* Output pixels */
  64   png_color_16  bg;                     /* Background color */
  65
  66
  67  /*
  68   * Setup the PNG data structures...
  69   */
  70
  71   pp   = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  72   info = png_create_info_struct(pp);
  73
  74  /*
  75   * Initialize the PNG read "engine"...
  76   */
  77
  78   png_init_io(pp, fp);
  79
  80  /*
  81   * Get the image dimensions and load the output image...
  82   */
  83
  84   png_read_info(pp, info);
  85
  86   png_get_IHDR(pp, info, &width, &height, &bit_depth, &color_type,
  87                &interlace_type, &compression_type, &filter_type);
  88
  89   fprintf(stderr, "DEBUG: PNG image: %dx%dx%d, color_type=%x (%s%s%s)\n",
  90           (int)width, (int)height, bit_depth, color_type,
  91           (color_type & PNG_COLOR_MASK_COLOR) ? "RGB" : "GRAYSCALE",
  92           (color_type & PNG_COLOR_MASK_ALPHA) ? "+ALPHA" : "",
  93           (color_type & PNG_COLOR_MASK_PALETTE) ? "+PALETTE" : "");
  94
  95   if (color_type & PNG_COLOR_MASK_PALETTE)
  96     png_set_expand(pp);
  97   else if (bit_depth < 8)
  98   {
  99     png_set_packing(pp);
 100     png_set_expand(pp);
 101   }
 102   else if (bit_depth == 16)
 103     png_set_strip_16(pp);
 104
 105   if (color_type & PNG_COLOR_MASK_COLOR)
 106     img->colorspace = (primary == CUPS_IMAGE_RGB_CMYK) ? CUPS_IMAGE_RGB :
 107                                                          primary;
 108   else
 109     img->colorspace = secondary;
 110
 111   if (width == 0 || width > CUPS_IMAGE_MAX_WIDTH ||
 112       height == 0 || height > CUPS_IMAGE_MAX_HEIGHT)
 113   {
 114     fprintf(stderr, "DEBUG: PNG image has invalid dimensions %ux%u!\n",
 115             (unsigned)width, (unsigned)height);
 116     fclose(fp);
 117     return (1);
 118   }
 119
 120   img->xsize = width;
 121   img->ysize = height;
 122
 123   if ((xppm = png_get_x_pixels_per_meter(pp, info)) != 0 &&
 124       (yppm = png_get_y_pixels_per_meter(pp, info)) != 0)
 125   {
 126     img->xppi = (int)((float)xppm * 0.0254);
 127     img->yppi = (int)((float)yppm * 0.0254);
 128
 129     if (img->xppi == 0 || img->yppi == 0)
 130     {
 131       fprintf(stderr, "DEBUG: PNG image has invalid resolution %dx%d PPI\n",
 132               img->xppi, img->yppi);
 133
 134       img->xppi = img->yppi = 128;
 135     }
 136   }
 137
 138   cupsImageSetMaxTiles(img, 0);
 139
 140   passes = png_set_interlace_handling(pp);
 141
 142  /*
 143   * Handle transparency...
 144   */
 145
 146   if (png_get_valid(pp, info, PNG_INFO_tRNS))
 147     png_set_tRNS_to_alpha(pp);
 148
 149   bg.red   = 65535;
 150   bg.green = 65535;
 151   bg.blue  = 65535;
 152
 153   png_set_background(pp, &bg, PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 154
 155   if (passes == 1)
 156   {
 157    /*
 158     * Load one row at a time...
 159     */
 160
 161     if (color_type == PNG_COLOR_TYPE_GRAY ||
 162         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 163       in = malloc(img->xsize);
 164     else
 165       in = malloc(img->xsize * 3);
 166   }
 167   else
 168   {
 169    /*
 170     * Interlaced images must be loaded all at once...
 171     */
 172
 173     if (color_type == PNG_COLOR_TYPE_GRAY ||
 174         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 175       in = malloc(img->xsize * img->ysize);
 176     else
 177       in = malloc(img->xsize * img->ysize * 3);
 178   }
 179
 180   bpp = cupsImageGetDepth(img);
 181   out = malloc(img->xsize * bpp);
 182
 183  /*
 184   * Read the image, interlacing as needed...
 185   */
 186
 187   for (pass = 1; pass <= passes; pass ++)
 188     for (inptr = in, y = 0; y < img->ysize; y ++)
 189     {
 190       png_read_row(pp, (png_bytep)inptr, NULL);
 191
 192       if (pass == passes)
 193       {
 194        /*
 195         * Output this row...
 196         */
 197
 198         if (color_type & PNG_COLOR_MASK_COLOR)
 199         {
 200           if ((saturation != 100 || hue != 0) && bpp > 1)
 201             cupsImageRGBAdjust(inptr, img->xsize, saturation, hue);
 202
 203           switch (img->colorspace)
 204           {
 205             case CUPS_IMAGE_WHITE :
 206                 cupsImageRGBToWhite(inptr, out, img->xsize);
 207                 break;
 208             case CUPS_IMAGE_RGB :
 209             case CUPS_IMAGE_RGB_CMYK :
 210                 cupsImageRGBToRGB(inptr, out, img->xsize);
 211                 break;
 212             case CUPS_IMAGE_BLACK :
 213                 cupsImageRGBToBlack(inptr, out, img->xsize);
 214                 break;
 215             case CUPS_IMAGE_CMY :
 216                 cupsImageRGBToCMY(inptr, out, img->xsize);
 217                 break;
 218             case CUPS_IMAGE_CMYK :
 219                 cupsImageRGBToCMYK(inptr, out, img->xsize);
 220                 break;
 221           }
 222         }
 223         else
 224         {
 225           switch (img->colorspace)
 226           {
 227             case CUPS_IMAGE_WHITE :
 228                 memcpy(out, inptr, img->xsize);
 229                 break;
 230             case CUPS_IMAGE_RGB :
 231             case CUPS_IMAGE_RGB_CMYK :
 232                 cupsImageWhiteToRGB(inptr, out, img->xsize);
 233                 break;
 234             case CUPS_IMAGE_BLACK :
 235                 cupsImageWhiteToBlack(inptr, out, img->xsize);
 236                 break;
 237             case CUPS_IMAGE_CMY :
 238                 cupsImageWhiteToCMY(inptr, out, img->xsize);
 239                 break;
 240             case CUPS_IMAGE_CMYK :
 241                 cupsImageWhiteToCMYK(inptr, out, img->xsize);
 242                 break;
 243           }
 244         }
 245
 246         if (lut)
 247           cupsImageLut(out, img->xsize * bpp, lut);
 248
 249         _cupsImagePutRow(img, 0, y, img->xsize, out);
 250       }
 251
 252       if (passes > 1)
 253       {
 254         if (color_type & PNG_COLOR_MASK_COLOR)
 255           inptr += img->xsize * 3;
 256         else
 257           inptr += img->xsize;
 258       }
 259     }
 260
 261   png_read_end(pp, info);
 262   png_destroy_read_struct(&pp, &info, NULL);
 263
 264   fclose(fp);
 265   free(in);
 266   free(out);
 267
 268   return (0);
 269 }
 270 #endif /* HAVE_LIBPNG && HAVE_LIBZ */
 271
 272
 273 /*
 274  * End of "$Id: image-png.c 6649 2007-07-11 21:46:42Z mike $".
 275  */