Constructor Detail

• OneDReader

  public OneDReader()

Method Detail

• decode

  public Result decode(BinaryBitmap image)
                throws NotFoundException,
                       FormatException

  Description copied from interface: Reader
  Locates and decodes a barcode in some format within an image.

  Specified by:

  decode in interface  Reader

  Parameters:

  image - image of barcode to decode

  Returns:

  String which the barcode encodes

  Throws:

  NotFoundException - if no potential barcode is found

  FormatException - if a potential barcode is found but format is invalid

• decode

  public Result decode(BinaryBitmap image,
                       Map<DecodeHintType,?> hints)
                throws NotFoundException,
                       FormatException

  Description copied from interface: Reader
  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.

  Specified by:

  decode in interface  Reader

  Parameters:

  image - image of barcode to decode

  hints - passed as a Map from 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.

  Returns:

  String which the barcode encodes

  Throws:

  NotFoundException - if no potential barcode is found

  FormatException - if a potential barcode is found but format is invalid

• reset

  public void reset()

  Description copied from interface: Reader
  Resets any internal state the implementation has after a decode, to prepare it for reuse.

• recordPattern

  protected static void recordPattern(BitArray row,
                                      int start,
                                      int[] counters)
                               throws NotFoundException

  Records the size of successive runs of white and black pixels in a row, starting at a given point. The values are recorded in the given array, and the number of runs recorded is equal to the size of the array. If the row starts on a white pixel at the given start point, then the first count recorded is the run of white pixels starting from that point; likewise it is the count of a run of black pixels if the row begin on a black pixels at that point.

  Parameters:

  row - row to count from

  start - offset into row to start at

  counters - array into which to record counts

  Throws:

  NotFoundException - if counters cannot be filled entirely from row before running out of pixels

• recordPatternInReverse

  protected static void recordPatternInReverse(BitArray row,
                                               int start,
                                               int[] counters)
                                        throws NotFoundException

  Throws:

  NotFoundException

• patternMatchVariance

  protected static float patternMatchVariance(int[] counters,
                                              int[] pattern,
                                              float maxIndividualVariance)

  Determines how closely a set of observed counts of runs of black/white values matches a given target pattern. This is reported as the ratio of the total variance from the expected pattern proportions across all pattern elements, to the length of the pattern.

  Parameters:

  counters - observed counters

  pattern - expected pattern

  maxIndividualVariance - The most any counter can differ before we give up

  Returns:

  ratio of total variance between counters and pattern compared to total pattern size

• decodeRow

  public abstract Result decodeRow(int rowNumber,
                                   BitArray row,
                                   Map<DecodeHintType,?> hints)
                            throws NotFoundException,
                                   ChecksumException,
                                   FormatException

  Attempts to decode a one-dimensional barcode format given a single row of an image.

  Parameters:

  rowNumber - row number from top of the row

  row - the black/white pixel data of the row

  hints - decode hints

  Returns:

  Result containing encoded string and start/end of barcode

  Throws:

  NotFoundException - if no potential barcode is found

  ChecksumException - if a potential barcode is found but does not pass its checksum

  FormatException - if a potential barcode is found but format is invalid