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#include <png.h>
#include <stdio.h>
#include <stdlib.h>
#include <zbar.h>
#if !defined(PNG_LIBPNG_VER) || PNG_LIBPNG_VER < 10018 || \
(PNG_LIBPNG_VER > 10200 && PNG_LIBPNG_VER < 10209)
/* Changes to Libpng from version 1.2.42 to 1.4.0 (January 4, 2010)
* ...
* 2. m. The function png_set_gray_1_2_4_to_8() was removed. It has been
* deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
* png_set_expand_gray_1_2_4_to_8() because the former function also
* expanded palette images.
*/
#define png_set_expand_gray_1_2_4_to_8 png_set_gray_1_2_4_to_8
#endif
zbar_image_scanner_t *scanner = NULL;
/* to complete a runnable example, this abbreviated implementation of
* get_data() will use libpng to read an image file. refer to libpng
* documentation for details
*/
static void get_data(const char *name, int *width, int *height, void **raw)
{
png_structp png;
png_infop info;
int color, bits;
png_bytep *rows;
int i;
FILE *file = fopen(name, "rb");
if (!file)
exit(2);
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png)
exit(3);
if (setjmp(png_jmpbuf(png)))
exit(4);
info = png_create_info_struct(png);
if (!info)
exit(5);
png_init_io(png, file);
png_read_info(png, info);
/* configure for 8bpp grayscale input */
color = png_get_color_type(png, info);
bits = png_get_bit_depth(png, info);
if (color & PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if (color == PNG_COLOR_TYPE_GRAY && bits < 8)
png_set_expand_gray_1_2_4_to_8(png);
if (bits == 16)
png_set_strip_16(png);
if (color & PNG_COLOR_MASK_ALPHA)
png_set_strip_alpha(png);
if (color & PNG_COLOR_MASK_COLOR)
png_set_rgb_to_gray_fixed(png, 1, -1, -1);
/* allocate image */
*width = png_get_image_width(png, info);
*height = png_get_image_height(png, info);
*raw = (png_bytep)calloc(*width * *height, sizeof(png_byte));
rows = (png_bytep *)calloc(*height, sizeof(*rows));
for (i = 0; i < *height; i++)
rows[i] = ((png_bytep)(*raw)) + (*width * i);
png_read_image(png, rows);
free(rows);
}
int main(int argc, char **argv)
{
int width, height, n;
void *raw;
zbar_image_t *image;
const zbar_symbol_t *symbol;
if (argc < 2)
return (1);
/* create a reader */
scanner = zbar_image_scanner_create();
/* configure the reader */
zbar_image_scanner_set_config(scanner, 0, ZBAR_CFG_ENABLE, 1);
/* obtain image data */
width = 0, height = 0;
raw = NULL;
get_data(argv[1], &width, &height, &raw);
/* wrap image data */
image = zbar_image_create();
zbar_image_set_format(image, zbar_fourcc('Y', '8', '0', '0'));
zbar_image_set_size(image, width, height);
zbar_image_set_data(image, raw, width * height, zbar_image_free_data);
/* scan the image for barcodes */
n = zbar_scan_image(scanner, image);
/* extract results */
symbol = zbar_image_first_symbol(image);
for (; symbol; symbol = zbar_symbol_next(symbol)) {
/* do something useful with results */
zbar_symbol_type_t typ = zbar_symbol_get_type(symbol);
const char *data = zbar_symbol_get_data(symbol);
printf("decoded %s symbol \"%s\"\n", zbar_get_symbol_name(typ), data);
}
/* clean up */
zbar_image_destroy(image);
zbar_image_scanner_destroy(scanner);
return (0);
}
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