1 files changed, 117 insertions, 0 deletions
diff --git a/examples/scan_image.c b/examples/scan_image.c
new file mode 100644
index 0000000..a44b58c
--- /dev/null
+++ b/examples/scan_image.c
@@ -0,0 +1,117 @@
+#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);
+}