quirc/lib/quirc.h
2012-05-04 12:58:42 +12:00

141 lines
4.3 KiB
C

/* quirc -- QR-code recognition library
* Copyright (C) 2010-2012 Daniel Beer <dlbeer@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef QUIRC_H_
#define QUIRC_H_
#include <stdint.h>
struct quirc;
/* Obtain the library version string. */
const char *quirc_version(void);
/* Construct a new QR-code recognizer. This function will return NULL
* if sufficient memory could not be allocated.
*/
struct quirc *quirc_new(void);
/* Destroy a QR-code recognizer. */
void quirc_destroy(struct quirc *q);
/* Resize the QR-code recognizer. The size of an image must be
* specified before codes can be analyzed.
*
* This function returns 0 on success, or -1 if sufficient memory could
* not be allocated.
*/
int quirc_resize(struct quirc *q, int w, int h);
/* These functions are used to process images for QR-code recognition.
* quirc_begin() must first be called to obtain access to a buffer into
* which the input image should be placed. Optionally, the current
* width and height may be returned.
*
* After filling the buffer, quirc_end() should be called to process
* the image for QR-code recognition. The locations and content of each
* code may be obtained using accessor functions described below.
*/
uint8_t *quirc_begin(struct quirc *q, int *w, int *h);
void quirc_end(struct quirc *q);
/* This structure describes a location in the input image buffer. */
struct quirc_point {
int x;
int y;
};
/* This enum describes the various decoder errors which may occur. */
typedef enum {
QUIRC_SUCCESS = 0,
QUIRC_ERROR_INVALID_GRID_SIZE,
QUIRC_ERROR_INVALID_VERSION,
QUIRC_ERROR_FORMAT_ECC,
QUIRC_ERROR_DATA_ECC,
QUIRC_ERROR_UNKNOWN_DATA_TYPE,
QUIRC_ERROR_DATA_OVERFLOW,
QUIRC_ERROR_DATA_UNDERFLOW
} quirc_decode_error_t;
/* Return a string error message for an error code. */
const char *quirc_strerror(quirc_decode_error_t err);
/* Limits on the maximum size of QR-codes and their content. */
#define QUIRC_MAX_BITMAP 3917
#define QUIRC_MAX_PAYLOAD 8896
/* QR-code ECC types. */
#define QUIRC_ECC_LEVEL_M 0
#define QUIRC_ECC_LEVEL_L 1
#define QUIRC_ECC_LEVEL_H 2
#define QUIRC_ECC_LEVEL_Q 3
/* QR-code data types. */
#define QUIRC_DATA_TYPE_NUMERIC 1
#define QUIRC_DATA_TYPE_ALPHA 2
#define QUIRC_DATA_TYPE_BYTE 4
#define QUIRC_DATA_TYPE_KANJI 8
/* This structure is used to return information about detected QR codes
* in the input image.
*/
struct quirc_code {
/* The four corners of the QR-code, from top left, clockwise */
struct quirc_point corners[4];
/* The number of cells across in the QR-code. The cell bitmap
* is a bitmask giving the actual values of cells. If the cell
* at (x, y) is black, then the following bit is set:
*
* cell_bitmap[i << 3] & (1 << (i & 7))
*
* where i = (y * size) + x.
*/
int size;
uint8_t cell_bitmap[QUIRC_MAX_BITMAP];
};
/* This structure holds the decoded QR-code data */
struct quirc_data {
/* Various parameters of the QR-code. These can mostly be
* ignored if you only care about the data.
*/
int version;
int ecc_level;
int mask;
int data_type;
/* Data payload. For the Kanji datatype, payload is encoded as
* Shift-JIS. For all other datatypes, payload is ASCII text.
*/
uint8_t payload[QUIRC_MAX_PAYLOAD];
int payload_len;
};
/* Return the number of QR-codes identified in the last processed
* image.
*/
int quirc_count(const struct quirc *q);
/* Extract the QR-code specified by the given index. */
void quirc_extract(const struct quirc *q, int index,
struct quirc_code *code);
/* Decode a QR-code, returning the payload data. */
quirc_decode_error_t quirc_decode(const struct quirc_code *code,
struct quirc_data *data);
#endif