scan_image.c

00001 #include <stdio.h>
00002 #include <stdlib.h>
00003 #if (0) //  png is not used
00004 #include <png.h>
00005 #endif
00006 #include <zbar.h>
00007 
00008 zbar_image_scanner_t *scanner = NULL;
00009 
00010 /* to complete a runnable example, this abbreviated implementation of
00011  * get_data() will use libpng to read an image file. refer to libpng
00012  * documentation for details
00013  */
00014 #if (0) //  png is not used
00015 static void get_data (const char *name,
00016                       int *width, int *height,
00017                       void **raw)
00018 {
00019     FILE *file = fopen(name, "rb");
00020     if(!file) exit(2);
00021     png_structp png =
00022         png_create_read_struct(PNG_LIBPNG_VER_STRING,
00023                                NULL, NULL, NULL);
00024     if(!png) exit(3);
00025     if(setjmp(png_jmpbuf(png))) exit(4);
00026     png_infop info = png_create_info_struct(png);
00027     if(!info) exit(5);
00028     png_init_io(png, file);
00029     png_read_info(png, info);
00030     /* configure for 8bpp grayscale input */
00031     int color = png_get_color_type(png, info);
00032     int bits = png_get_bit_depth(png, info);
00033     if(color & PNG_COLOR_TYPE_PALETTE)
00034         png_set_palette_to_rgb(png);
00035     if(color == PNG_COLOR_TYPE_GRAY && bits < 8)
00036         png_set_gray_1_2_4_to_8(png);
00037     if(bits == 16)
00038         png_set_strip_16(png);
00039     if(color & PNG_COLOR_MASK_ALPHA)
00040         png_set_strip_alpha(png);
00041     if(color & PNG_COLOR_MASK_COLOR)
00042         png_set_rgb_to_gray_fixed(png, 1, -1, -1);
00043     /* allocate image */
00044     *width = png_get_image_width(png, info);
00045     *height = png_get_image_height(png, info);
00046     *raw = malloc(*width * *height);
00047     png_bytep rows[*height];
00048     int i;
00049     for(i = 0; i < *height; i++)
00050         rows[i] = *raw + (*width * i);
00051     png_read_image(png, rows);
00052 }
00053 #endif  //  png is not used
00054 #if (1) //  function name and arguments are changed.
00055 int zbar_main (void* image_buff, int width, int height)
00056 #else
00057 int main (int argc, char **argv)
00058 #endif
00059 {
00060 #if (1) //  arguments are changed
00061     if((image_buff == NULL)||(width < 1)||(height < 1)) return(1);
00062 #else
00063     if(argc < 2) return(1);
00064 #endif
00065 
00066     /* create a reader */
00067     scanner = zbar_image_scanner_create();
00068 
00069     /* configure the reader */
00070     zbar_image_scanner_set_config(scanner, 0, ZBAR_CFG_ENABLE, 1);
00071 
00072     /* obtain image data */
00073 #if (1) //  width, height, raw data are fixed
00074     void *raw = image_buff;
00075 #else
00076     int width = 0, height = 0;
00077     void *raw = NULL;
00078     get_data(argv[1], &width, &height, &raw);
00079 #endif
00080 
00081     /* wrap image data */
00082     zbar_image_t *image = zbar_image_create();
00083     zbar_image_set_format(image, *(int*)"Y800");
00084     zbar_image_set_size(image, width, height);
00085     zbar_image_set_data(image, raw, width * height, zbar_image_free_data);
00086 
00087     /* scan the image for barcodes */
00088     int n = zbar_scan_image(scanner, image);
00089 
00090     /* extract results */
00091     const zbar_symbol_t *symbol = zbar_image_first_symbol(image);
00092     if ( symbol ) {
00093         for(; symbol; symbol = zbar_symbol_next(symbol)) {
00094             /* do something useful with results */
00095             zbar_symbol_type_t typ = zbar_symbol_get_type(symbol);
00096             const char *data = zbar_symbol_get_data(symbol);
00097             printf("decoded %s symbol \"%s\"\n",
00098                    zbar_get_symbol_name(typ), data);
00099         }
00100     }
00101     else {
00102         printf("No Code detected.\n");
00103     }
00104 
00105     /* clean up */
00106     zbar_image_destroy(image);
00107     zbar_image_scanner_destroy(scanner);
00108 
00109     return(0);
00110 }
00111