Interface Reader

core/src/main/java/com/google/zxing/Reader.java:33–69

Implementations of this interface can decode an image of a barcode in some format into the String it encodes. For example, com.google.zxing.qrcode.QRCodeReader can decode a QR code. The decoder may optionally receive hints from the caller which may help it decode more quickly or accurately.

 * @author dswitkin@google.com (Daniel Switkin)
 */
public interface Reader {

  /**
   * Locates and decodes a barcode in some format within an image.
   *
   * @param image image of barcode to decode
   * @return String which the barcode encodes
   * @throws NotFoundException if no potential barcode is found
   * @throws ChecksumException if a potential barcode is found but does not pass its checksum
   * @throws FormatException if a potential barcode is found but format is invalid
   */
  Result decode(BinaryBitmap image) throws NotFoundException, ChecksumException, FormatException;

  /**
   * Locates and decodes a barcode in some format within an image. This method also accepts
   * hints, each possibly associated to some data, which may help the implementation decode.
   *
   * @param image image of barcode to decode
   * @param hints passed as a {@link Map} from {@link DecodeHintType}
   * to arbitrary data. The
   * meaning of the data depends upon the hint type. The implementation may or may not do
   * anything with these hints.
   * @return String which the barcode encodes
   * @throws NotFoundException if no potential barcode is found
   * @throws ChecksumException if a potential barcode is found but does not pass its checksum
   * @throws FormatException if a potential barcode is found but format is invalid
   */
  Result decode(BinaryBitmap image, Map<DecodeHintType,?> hints)
      throws NotFoundException, ChecksumException, FormatException;

  /**
   * Resets any internal state the implementation has after a decode, to prepare it
   * for reuse.
   */
  void reset();

}