2 * Image Library -- libpng
4 * (c) 2006 Pavel Charvat <pchar@ucw.cz>
6 * This software may be freely distributed and used according to the terms
7 * of the GNU Lesser General Public License.
13 #include "lib/mempool.h"
14 #include "lib/fastbuf.h"
15 #include "images/images.h"
19 struct libpng_read_data {
30 libpng_malloc(png_structp png_ptr, png_size_t size)
32 DBG("libpng_malloc(size=%u)", (uns)size);
33 return mp_alloc(png_get_mem_ptr(png_ptr), size);
37 libpng_free(png_structp png_ptr UNUSED, png_voidp ptr UNUSED)
43 libpng_read_error(png_structp png_ptr, png_const_charp msg)
45 DBG("libpng_read_error()");
46 image_thread_err(png_get_error_ptr(png_ptr), IMAGE_ERR_READ_FAILED, (byte *)msg);
47 longjmp(png_jmpbuf(png_ptr), 1);
51 libpng_write_error(png_structp png_ptr, png_const_charp msg)
53 DBG("libpng_write_error()");
54 image_thread_err(png_get_error_ptr(png_ptr), IMAGE_ERR_WRITE_FAILED, (byte *)msg);
55 longjmp(png_jmpbuf(png_ptr), 1);
59 libpng_warning(png_structp png_ptr UNUSED, png_const_charp msg UNUSED)
61 DBG("libpng_warning(): %s", (byte *)msg);
65 libpng_read_fn(png_structp png_ptr, png_bytep data, png_size_t length)
67 DBG("libpng_read_fn(len=%u)", (uns)length);
68 if (unlikely(bread((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length) < length))
69 png_error(png_ptr, "Incomplete data");
73 libpng_write_fn(png_structp png_ptr, png_bytep data, png_size_t length)
75 DBG("libpng_write_fn(len=%u)", (uns)length);
76 bwrite((struct fastbuf *)png_get_io_ptr(png_ptr), (byte *)data, length);
80 libpng_flush_fn(png_structp png_ptr UNUSED)
82 DBG("libpng_flush_fn()");
86 libpng_read_cancel(struct image_io *io)
88 DBG("libpng_read_cancel()");
90 struct libpng_read_data *rd = io->read_data;
91 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
95 libpng_read_header(struct image_io *io)
97 DBG("libpng_read_header()");
99 /* Create libpng structures */
100 struct libpng_read_data *rd = io->read_data = mp_alloc(io->internal_pool, sizeof(*rd));
101 rd->png_ptr = png_create_read_struct_2(PNG_LIBPNG_VER_STRING,
102 io->thread, libpng_read_error, libpng_warning,
103 io->internal_pool, libpng_malloc, libpng_free);
104 if (unlikely(!rd->png_ptr))
106 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng read structure.");
109 rd->info_ptr = png_create_info_struct(rd->png_ptr);
110 if (unlikely(!rd->info_ptr))
112 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng info structure.");
113 png_destroy_read_struct(&rd->png_ptr, NULL, NULL);
116 rd->end_ptr = png_create_info_struct(rd->png_ptr);
117 if (unlikely(!rd->end_ptr))
119 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Cannot create libpng info structure.");
120 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, NULL);
124 /* Setup libpng longjump */
125 if (unlikely(setjmp(png_jmpbuf(rd->png_ptr))))
127 DBG("Libpng failed to read the image, longjump saved us");
128 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
132 /* Setup libpng IO */
133 png_set_read_fn(rd->png_ptr, io->fastbuf, libpng_read_fn);
134 png_set_user_limits(rd->png_ptr, IMAGE_MAX_SIZE, IMAGE_MAX_SIZE);
137 png_read_info(rd->png_ptr, rd->info_ptr);
138 png_get_IHDR(rd->png_ptr, rd->info_ptr, &rd->cols, &rd->rows, &rd->bit_depth, &rd->color_type, NULL, NULL, NULL);
140 /* Fill image_io values */
145 if (!(io->flags & IMAGE_CHANNELS_FORMAT))
146 switch (rd->color_type)
148 case PNG_COLOR_TYPE_GRAY:
149 io->flags |= COLOR_SPACE_GRAYSCALE;
151 case PNG_COLOR_TYPE_GRAY_ALPHA:
152 io->flags |= COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA;
154 case PNG_COLOR_TYPE_RGB:
155 io->flags |= COLOR_SPACE_RGB;
157 case PNG_COLOR_TYPE_RGB_ALPHA:
158 case PNG_COLOR_TYPE_PALETTE:
159 io->flags |= COLOR_SPACE_RGB | IMAGE_ALPHA;
162 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
163 image_thread_err(io->thread, IMAGE_ERR_READ_FAILED, "Unknown color type");
168 io->read_cancel = libpng_read_cancel;
173 libpng_read_data(struct image_io *io)
175 DBG("libpng_read_data()");
177 struct libpng_read_data *rd = io->read_data;
179 /* Test supported pixel formats */
180 switch (io->flags & IMAGE_COLOR_SPACE)
182 case COLOR_SPACE_GRAYSCALE:
183 case COLOR_SPACE_RGB:
186 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
187 image_thread_err(io->thread, IMAGE_ERR_INVALID_PIXEL_FORMAT, "Unsupported color space.");
191 volatile int need_scale = io->cols != rd->cols || io->rows != rd->rows;
192 struct image * volatile img = need_scale ?
193 image_new(io->thread, rd->cols, rd->rows, io->flags & IMAGE_PIXEL_FORMAT, NULL) :
194 image_new(io->thread, rd->cols, rd->rows, io->flags, io->pool);
197 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
201 if (setjmp(png_jmpbuf(rd->png_ptr)))
203 DBG("Libpng failed to read the image, longjump saved us");
204 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
205 if (need_scale || !io->pool)
206 image_destroy(io->thread, img);
210 /* Apply transformations */
211 if (rd->bit_depth == 16)
212 png_set_strip_16(rd->png_ptr);
213 switch (rd->color_type)
215 case PNG_COLOR_TYPE_PALETTE:
216 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
218 png_set_palette_to_rgb(rd->png_ptr);
219 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
222 png_set_palette_to_rgb(rd->png_ptr);
223 if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
224 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
226 png_set_strip_alpha(rd->png_ptr);
228 case PNG_COLOR_TYPE_GRAY:
229 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_RGB)
230 png_set_gray_to_rgb(rd->png_ptr);
231 if (io->flags & IMAGE_ALPHA)
232 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
234 case PNG_COLOR_TYPE_GRAY_ALPHA:
235 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_RGB)
236 png_set_gray_to_rgb(rd->png_ptr);
237 if (!(io->flags & IMAGE_ALPHA))
238 png_set_strip_alpha(rd->png_ptr);
240 case PNG_COLOR_TYPE_RGB:
241 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
242 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
243 if ((io->flags & IMAGE_ALPHA) || (io->flags & IMAGE_PIXEL_FORMAT) == (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
244 png_set_add_alpha(rd->png_ptr, 255, PNG_FILLER_AFTER);
246 case PNG_COLOR_TYPE_RGB_ALPHA:
247 if ((io->flags & IMAGE_COLOR_SPACE) == COLOR_SPACE_GRAYSCALE)
248 png_set_rgb_to_gray_fixed(rd->png_ptr, 1, 21267, 71514);
249 if (!(io->flags & IMAGE_ALPHA) && (io->flags & IMAGE_PIXEL_FORMAT) != (COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED))
250 png_set_strip_alpha(rd->png_ptr);
255 png_read_update_info(rd->png_ptr, rd->info_ptr);
257 /* Read image data */
258 DBG("Reading image data");
259 byte *pixels = img->pixels;
260 png_bytep rows[img->rows];
261 for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
262 rows[r] = (png_bytep)pixels;
263 png_read_image(rd->png_ptr, rows);
264 png_read_end(rd->png_ptr, rd->end_ptr);
266 /* Destroy libpng read structure */
267 png_destroy_read_struct(&rd->png_ptr, &rd->info_ptr, &rd->end_ptr);
269 /* Scale and store the resulting image */
272 struct image *dest = image_new(io->thread, io->cols, io->rows, io->flags, io->pool);
275 image_destroy(io->thread, img);
278 if (!image_scale(io->thread, dest, img))
280 image_destroy(io->thread, img);
282 image_destroy(io->thread, dest);
289 io->image_destroy = !io->pool;
295 libpng_write(struct image_io *io)
297 DBG("libpng_write()");
299 /* Create libpng structures */
300 png_structp png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
301 io->thread, libpng_write_error, libpng_warning,
302 io->internal_pool, libpng_malloc, libpng_free);
303 if (unlikely(!png_ptr))
305 image_thread_err(io->thread, IMAGE_ERR_WRITE_FAILED, "Cannot create libpng write structure.");
308 png_infop info_ptr = png_create_info_struct(png_ptr);
309 if (unlikely(!info_ptr))
311 image_thread_err(io->thread, IMAGE_ERR_WRITE_FAILED, "Cannot create libpng info structure.");
312 png_destroy_write_struct(&png_ptr, NULL);
316 /* Setup libpng longjump */
317 if (unlikely(setjmp(png_jmpbuf(png_ptr))))
319 DBG("Libpng failed to write the image, longjump saved us.");
320 png_destroy_write_struct(&png_ptr, &info_ptr);
324 /* Setup libpng IO */
325 png_set_write_fn(png_ptr, io->fastbuf, libpng_write_fn, libpng_flush_fn);
327 /* Setup PNG parameters */
328 struct image *img = io->image;
329 switch (img->flags & IMAGE_PIXEL_FORMAT)
331 case COLOR_SPACE_GRAYSCALE | IMAGE_PIXELS_ALIGNED:
332 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY,
333 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
335 case COLOR_SPACE_GRAYSCALE | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
336 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_GRAY_ALPHA,
337 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
339 case COLOR_SPACE_RGB:
340 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
341 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
343 case COLOR_SPACE_RGB | IMAGE_ALPHA | IMAGE_PIXELS_ALIGNED:
344 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB_ALPHA,
345 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
347 case COLOR_SPACE_RGB | IMAGE_PIXELS_ALIGNED:
348 png_set_IHDR(png_ptr, info_ptr, img->cols, img->rows, 8, PNG_COLOR_TYPE_RGB,
349 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
350 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
355 png_write_info(png_ptr, info_ptr);
358 byte *pixels = img->pixels;
359 png_bytep rows[img->rows];
360 for (uns r = 0; r < img->rows; r++, pixels += img->row_size)
361 rows[r] = (png_bytep)pixels;
362 png_write_image(png_ptr, rows);
363 png_write_end(png_ptr, info_ptr);
365 /* Free libpng structure */
366 png_destroy_write_struct(&png_ptr, &info_ptr);