2 * "$Id: image-png.c 9771 2011-05-12 05:21:56Z mike $"
4 * PNG image routines for CUPS.
6 * Copyright 2007-2011 by Apple Inc.
7 * Copyright 1993-2007 by Easy Software Products.
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/".
15 * This file is subject to the Apple OS-Developed Software exception.
19 * _cupsImageReadPNG() - Read a PNG image file.
23 * Include necessary headers...
26 #include "image-private.h"
28 #if defined(HAVE_LIBPNG) && defined(HAVE_LIBZ)
29 # include <png.h> /* Portable Network Graphics (PNG) definitions */
33 * '_cupsImageReadPNG()' - Read a PNG image file.
36 int /* O - Read status */
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 */
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 */
68 * Setup the PNG data structures...
71 pp = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
72 info = png_create_info_struct(pp);
75 * Initialize the PNG read "engine"...
81 * Get the image dimensions and load the output image...
84 png_read_info(pp, info);
86 png_get_IHDR(pp, info, &width, &height, &bit_depth, &color_type,
87 &interlace_type, &compression_type, &filter_type);
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" : "");
95 if (color_type & PNG_COLOR_MASK_PALETTE)
97 else if (bit_depth < 8)
102 else if (bit_depth == 16)
103 png_set_strip_16(pp);
105 if (color_type & PNG_COLOR_MASK_COLOR)
106 img->colorspace = (primary == CUPS_IMAGE_RGB_CMYK) ? CUPS_IMAGE_RGB :
109 img->colorspace = secondary;
111 if (width == 0 || width > CUPS_IMAGE_MAX_WIDTH ||
112 height == 0 || height > CUPS_IMAGE_MAX_HEIGHT)
114 fprintf(stderr, "DEBUG: PNG image has invalid dimensions %ux%u!\n",
115 (unsigned)width, (unsigned)height);
123 if ((xppm = png_get_x_pixels_per_meter(pp, info)) != 0 &&
124 (yppm = png_get_y_pixels_per_meter(pp, info)) != 0)
126 img->xppi = (int)((float)xppm * 0.0254);
127 img->yppi = (int)((float)yppm * 0.0254);
129 if (img->xppi == 0 || img->yppi == 0)
131 fprintf(stderr, "DEBUG: PNG image has invalid resolution %dx%d PPI\n",
132 img->xppi, img->yppi);
134 img->xppi = img->yppi = 128;
138 cupsImageSetMaxTiles(img, 0);
140 passes = png_set_interlace_handling(pp);
143 * Handle transparency...
146 if (png_get_valid(pp, info, PNG_INFO_tRNS))
147 png_set_tRNS_to_alpha(pp);
153 png_set_background(pp, &bg, PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
158 * Load one row at a time...
161 if (color_type == PNG_COLOR_TYPE_GRAY ||
162 color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
163 in = malloc(img->xsize);
165 in = malloc(img->xsize * 3);
170 * Interlaced images must be loaded all at once...
173 size_t bufsize; /* Size of buffer */
176 if (color_type == PNG_COLOR_TYPE_GRAY ||
177 color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
179 bufsize = img->xsize * img->ysize;
181 if ((bufsize / img->xsize) != img->ysize)
183 fprintf(stderr, "DEBUG: PNG image dimensions (%ux%u) too large!\n",
184 (unsigned)width, (unsigned)height);
191 bufsize = img->xsize * img->ysize * 3;
193 if ((bufsize / (img->xsize * 3)) != img->ysize)
195 fprintf(stderr, "DEBUG: PNG image dimensions (%ux%u) too large!\n",
196 (unsigned)width, (unsigned)height);
202 in = malloc(bufsize);
205 bpp = cupsImageGetDepth(img);
206 out = malloc(img->xsize * bpp);
210 fputs("DEBUG: Unable to allocate memory for PNG image!\n", stderr);
224 * Read the image, interlacing as needed...
227 for (pass = 1; pass <= passes; pass ++)
228 for (inptr = in, y = 0; y < img->ysize; y ++)
230 png_read_row(pp, (png_bytep)inptr, NULL);
238 if (color_type & PNG_COLOR_MASK_COLOR)
240 if ((saturation != 100 || hue != 0) && bpp > 1)
241 cupsImageRGBAdjust(inptr, img->xsize, saturation, hue);
243 switch (img->colorspace)
245 case CUPS_IMAGE_WHITE :
246 cupsImageRGBToWhite(inptr, out, img->xsize);
248 case CUPS_IMAGE_RGB :
249 case CUPS_IMAGE_RGB_CMYK :
250 cupsImageRGBToRGB(inptr, out, img->xsize);
252 case CUPS_IMAGE_BLACK :
253 cupsImageRGBToBlack(inptr, out, img->xsize);
255 case CUPS_IMAGE_CMY :
256 cupsImageRGBToCMY(inptr, out, img->xsize);
258 case CUPS_IMAGE_CMYK :
259 cupsImageRGBToCMYK(inptr, out, img->xsize);
265 switch (img->colorspace)
267 case CUPS_IMAGE_WHITE :
268 memcpy(out, inptr, img->xsize);
270 case CUPS_IMAGE_RGB :
271 case CUPS_IMAGE_RGB_CMYK :
272 cupsImageWhiteToRGB(inptr, out, img->xsize);
274 case CUPS_IMAGE_BLACK :
275 cupsImageWhiteToBlack(inptr, out, img->xsize);
277 case CUPS_IMAGE_CMY :
278 cupsImageWhiteToCMY(inptr, out, img->xsize);
280 case CUPS_IMAGE_CMYK :
281 cupsImageWhiteToCMYK(inptr, out, img->xsize);
287 cupsImageLut(out, img->xsize * bpp, lut);
289 _cupsImagePutRow(img, 0, y, img->xsize, out);
294 if (color_type & PNG_COLOR_MASK_COLOR)
295 inptr += img->xsize * 3;
301 png_read_end(pp, info);
302 png_destroy_read_struct(&pp, &info, NULL);
310 #endif /* HAVE_LIBPNG && HAVE_LIBZ */
314 * End of "$Id: image-png.c 9771 2011-05-12 05:21:56Z mike $".