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annotate libs/imago/file_png.c @ 0:b2f14e535253

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author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 01 Feb 2014 19:58:19 +0200
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nuclear@0 1 /*
nuclear@0 2 libimago - a multi-format image file input/output library.
nuclear@0 3 Copyright (C) 2010 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0 4
nuclear@0 5 This program is free software: you can redistribute it and/or modify
nuclear@0 6 it under the terms of the GNU Lesser General Public License as published
nuclear@0 7 by the Free Software Foundation, either version 3 of the License, or
nuclear@0 8 (at your option) any later version.
nuclear@0 9
nuclear@0 10 This program is distributed in the hope that it will be useful,
nuclear@0 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@0 13 GNU Lesser General Public License for more details.
nuclear@0 14
nuclear@0 15 You should have received a copy of the GNU Lesser General Public License
nuclear@0 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@0 17 */
nuclear@0 18
nuclear@0 19 /* -- PNG module -- */
nuclear@0 20
nuclear@0 21 #include <stdlib.h>
nuclear@0 22 #include <png.h>
nuclear@0 23 #include "imago2.h"
nuclear@0 24 #include "ftype_module.h"
nuclear@0 25
nuclear@0 26 static int check_file(struct img_io *io);
nuclear@0 27 static int read_file(struct img_pixmap *img, struct img_io *io);
nuclear@0 28 static int write_file(struct img_pixmap *img, struct img_io *io);
nuclear@0 29
nuclear@0 30 static void read_func(png_struct *png, unsigned char *data, size_t len);
nuclear@0 31 static void write_func(png_struct *png, unsigned char *data, size_t len);
nuclear@0 32 static void flush_func(png_struct *png);
nuclear@0 33
nuclear@0 34 static int png_type_to_fmt(int color_type, int channel_bits);
nuclear@0 35 static int fmt_to_png_type(enum img_fmt fmt);
nuclear@0 36
nuclear@0 37
nuclear@0 38 int img_register_png(void)
nuclear@0 39 {
nuclear@0 40 static struct ftype_module mod = {".png", check_file, read_file, write_file};
nuclear@0 41 return img_register_module(&mod);
nuclear@0 42 }
nuclear@0 43
nuclear@0 44 static int check_file(struct img_io *io)
nuclear@0 45 {
nuclear@0 46 unsigned char sig[8];
nuclear@0 47 int res;
nuclear@0 48 long pos = io->seek(0, SEEK_CUR, io->uptr);
nuclear@0 49
nuclear@0 50 if(io->read(sig, 8, io->uptr) < 8) {
nuclear@0 51 io->seek(pos, SEEK_SET, io->uptr);
nuclear@0 52 return -1;
nuclear@0 53 }
nuclear@0 54
nuclear@0 55 res = png_sig_cmp(sig, 0, 8) == 0 ? 0 : -1;
nuclear@0 56 io->seek(pos, SEEK_SET, io->uptr);
nuclear@0 57 return res;
nuclear@0 58 }
nuclear@0 59
nuclear@0 60 static int read_file(struct img_pixmap *img, struct img_io *io)
nuclear@0 61 {
nuclear@0 62 png_struct *png;
nuclear@0 63 png_info *info;
nuclear@0 64 int channel_bits, color_type, ilace_type, compression, filtering, fmt;
nuclear@0 65 png_uint_32 xsz, ysz;
nuclear@0 66
nuclear@0 67 if(!(png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
nuclear@0 68 return -1;
nuclear@0 69 }
nuclear@0 70
nuclear@0 71 if(!(info = png_create_info_struct(png))) {
nuclear@0 72 png_destroy_read_struct(&png, 0, 0);
nuclear@0 73 return -1;
nuclear@0 74 }
nuclear@0 75
nuclear@0 76 if(setjmp(png_jmpbuf(png))) {
nuclear@0 77 png_destroy_read_struct(&png, &info, 0);
nuclear@0 78 return -1;
nuclear@0 79 }
nuclear@0 80
nuclear@0 81 png_set_read_fn(png, io, read_func);
nuclear@0 82 png_set_sig_bytes(png, 0);
nuclear@0 83 png_read_png(png, info, 0, 0);
nuclear@0 84
nuclear@0 85 png_get_IHDR(png, info, &xsz, &ysz, &channel_bits, &color_type, &ilace_type,
nuclear@0 86 &compression, &filtering);
nuclear@0 87 if((fmt = png_type_to_fmt(color_type, channel_bits)) == -1) {
nuclear@0 88 png_destroy_read_struct(&png, &info, 0);
nuclear@0 89 return -1;
nuclear@0 90 }
nuclear@0 91
nuclear@0 92 if(img_set_pixels(img, xsz, ysz, fmt, 0) == -1) {
nuclear@0 93 png_destroy_read_struct(&png, &info, 0);
nuclear@0 94 return -1;
nuclear@0 95 }
nuclear@0 96
nuclear@0 97
nuclear@0 98 if(channel_bits == 8) {
nuclear@0 99 unsigned int i;
nuclear@0 100 unsigned char **lineptr = (unsigned char**)png_get_rows(png, info);
nuclear@0 101 unsigned char *dest = img->pixels;
nuclear@0 102
nuclear@0 103 for(i=0; i<ysz; i++) {
nuclear@0 104 memcpy(dest, lineptr[i], xsz * img->pixelsz);
nuclear@0 105 dest += xsz * img->pixelsz;
nuclear@0 106 }
nuclear@0 107 } else {
nuclear@0 108 unsigned int i, j, num_elem;
nuclear@0 109 unsigned char **lineptr = (unsigned char**)png_get_rows(png, info);
nuclear@0 110 float *dest = img->pixels;
nuclear@0 111
nuclear@0 112 num_elem = img->pixelsz / sizeof(float);
nuclear@0 113 for(i=0; i<ysz; i++) {
nuclear@0 114 for(j=0; j<xsz * num_elem; j++) {
nuclear@0 115 unsigned short val = (lineptr[i][j * 2] << 8) | lineptr[i][j * 2 + 1];
nuclear@0 116 *dest++ = (float)val / 65535.0;
nuclear@0 117 }
nuclear@0 118 }
nuclear@0 119 }
nuclear@0 120
nuclear@0 121
nuclear@0 122 png_destroy_read_struct(&png, &info, 0);
nuclear@0 123 return 0;
nuclear@0 124 }
nuclear@0 125
nuclear@0 126
nuclear@0 127 static int write_file(struct img_pixmap *img, struct img_io *io)
nuclear@0 128 {
nuclear@0 129 png_struct *png;
nuclear@0 130 png_info *info;
nuclear@0 131 png_text txt;
nuclear@0 132 struct img_pixmap tmpimg;
nuclear@0 133 unsigned char **rows;
nuclear@0 134 unsigned char *pixptr;
nuclear@0 135 int i, coltype;
nuclear@0 136
nuclear@0 137 img_init(&tmpimg);
nuclear@0 138
nuclear@0 139 if(!(png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
nuclear@0 140 return -1;
nuclear@0 141 }
nuclear@0 142 if(!(info = png_create_info_struct(png))) {
nuclear@0 143 png_destroy_write_struct(&png, 0);
nuclear@0 144 return -1;
nuclear@0 145 }
nuclear@0 146
nuclear@0 147 /* if the input image is floating-point, we need to convert it to integer */
nuclear@0 148 if(img_is_float(img)) {
nuclear@0 149 if(img_copy(&tmpimg, img) == -1) {
nuclear@0 150 return -1;
nuclear@0 151 }
nuclear@0 152 if(img_to_integer(&tmpimg) == -1) {
nuclear@0 153 img_destroy(&tmpimg);
nuclear@0 154 return -1;
nuclear@0 155 }
nuclear@0 156 img = &tmpimg;
nuclear@0 157 }
nuclear@0 158
nuclear@0 159 txt.compression = PNG_TEXT_COMPRESSION_NONE;
nuclear@0 160 txt.key = "Software";
nuclear@0 161 txt.text = "libimago2";
nuclear@0 162 txt.text_length = 0;
nuclear@0 163
nuclear@0 164 if(setjmp(png_jmpbuf(png))) {
nuclear@0 165 png_destroy_write_struct(&png, &info);
nuclear@0 166 img_destroy(&tmpimg);
nuclear@0 167 return -1;
nuclear@0 168 }
nuclear@0 169 png_set_write_fn(png, io, write_func, flush_func);
nuclear@0 170
nuclear@0 171 coltype = fmt_to_png_type(img->fmt);
nuclear@0 172 png_set_IHDR(png, info, img->width, img->height, 8, coltype, PNG_INTERLACE_NONE,
nuclear@0 173 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
nuclear@0 174 png_set_text(png, info, &txt, 1);
nuclear@0 175
nuclear@0 176 if(!(rows = malloc(img->height * sizeof *rows))) {
nuclear@0 177 png_destroy_write_struct(&png, &info);
nuclear@0 178 img_destroy(&tmpimg);
nuclear@0 179 return -1;
nuclear@0 180 }
nuclear@0 181
nuclear@0 182 pixptr = img->pixels;
nuclear@0 183 for(i=0; i<img->height; i++) {
nuclear@0 184 rows[i] = pixptr;
nuclear@0 185 pixptr += img->width * img->pixelsz;
nuclear@0 186 }
nuclear@0 187 png_set_rows(png, info, rows);
nuclear@0 188
nuclear@0 189 png_write_png(png, info, 0, 0);
nuclear@0 190 png_write_end(png, info);
nuclear@0 191 png_destroy_write_struct(&png, &info);
nuclear@0 192
nuclear@0 193 free(rows);
nuclear@0 194
nuclear@0 195 img_destroy(&tmpimg);
nuclear@0 196 return 0;
nuclear@0 197 }
nuclear@0 198
nuclear@0 199 static void read_func(png_struct *png, unsigned char *data, size_t len)
nuclear@0 200 {
nuclear@0 201 struct img_io *io = (struct img_io*)png_get_io_ptr(png);
nuclear@0 202
nuclear@0 203 if(io->read(data, len, io->uptr) == -1) {
nuclear@0 204 longjmp(png_jmpbuf(png), 1);
nuclear@0 205 }
nuclear@0 206 }
nuclear@0 207
nuclear@0 208 static void write_func(png_struct *png, unsigned char *data, size_t len)
nuclear@0 209 {
nuclear@0 210 struct img_io *io = (struct img_io*)png_get_io_ptr(png);
nuclear@0 211
nuclear@0 212 if(io->write(data, len, io->uptr) == -1) {
nuclear@0 213 longjmp(png_jmpbuf(png), 1);
nuclear@0 214 }
nuclear@0 215 }
nuclear@0 216
nuclear@0 217 static void flush_func(png_struct *png)
nuclear@0 218 {
nuclear@0 219 /* XXX does it matter that we can't flush? */
nuclear@0 220 }
nuclear@0 221
nuclear@0 222 static int png_type_to_fmt(int color_type, int channel_bits)
nuclear@0 223 {
nuclear@0 224 /* only 8 and 16 bits per channel ar supported at the moment */
nuclear@0 225 if(channel_bits != 8 && channel_bits != 16) {
nuclear@0 226 return -1;
nuclear@0 227 }
nuclear@0 228
nuclear@0 229 switch(color_type) {
nuclear@0 230 case PNG_COLOR_TYPE_RGB:
nuclear@0 231 return channel_bits == 16 ? IMG_FMT_RGBF : IMG_FMT_RGB24;
nuclear@0 232
nuclear@0 233 case PNG_COLOR_TYPE_RGB_ALPHA:
nuclear@0 234 return channel_bits == 16 ? IMG_FMT_RGBAF : IMG_FMT_RGBA32;
nuclear@0 235
nuclear@0 236 case PNG_COLOR_TYPE_GRAY:
nuclear@0 237 return channel_bits == 16 ? IMG_FMT_GREYF : IMG_FMT_GREY8;
nuclear@0 238
nuclear@0 239 default:
nuclear@0 240 break;
nuclear@0 241 }
nuclear@0 242 return -1;
nuclear@0 243 }
nuclear@0 244
nuclear@0 245 static int fmt_to_png_type(enum img_fmt fmt)
nuclear@0 246 {
nuclear@0 247 switch(fmt) {
nuclear@0 248 case IMG_FMT_GREY8:
nuclear@0 249 return PNG_COLOR_TYPE_GRAY;
nuclear@0 250
nuclear@0 251 case IMG_FMT_RGB24:
nuclear@0 252 return PNG_COLOR_TYPE_RGB;
nuclear@0 253
nuclear@0 254 case IMG_FMT_RGBA32:
nuclear@0 255 return PNG_COLOR_TYPE_RGBA;
nuclear@0 256
nuclear@0 257 default:
nuclear@0 258 break;
nuclear@0 259 }
nuclear@0 260 return -1;
nuclear@0 261 }