Package com.google.zxing.oned

Class OneDReader

    • Constructor Summary

      Constructors 
      Constructor Description
      OneDReader()  

    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      Result decode​(BinaryBitmap image)
      Locates and decodes a barcode in some format within an image.
      Result decode​(BinaryBitmap image, java.util.Map<DecodeHintType,​?> hints)
      Locates and decodes a barcode in some format within an image.
      abstract Result decodeRow​(int rowNumber, BitArray row, java.util.Map<DecodeHintType,​?> hints)
      Attempts to decode a one-dimensional barcode format given a single row of an image.
      protected static int patternMatchVariance​(int[] counters, int[] pattern, int maxIndividualVariance)
      Determines how closely a set of observed counts of runs of black/white values matches a given target pattern.
      protected static void recordPattern​(BitArray row, int start, int[] counters)
      Records the size of successive runs of white and black pixels in a row, starting at a given point.
      protected static void recordPatternInReverse​(BitArray row, int start, int[] counters)  
      void reset()
      Resets any internal state the implementation has after a decode, to prepare it for reuse.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • PATTERN_MATCH_RESULT_SCALE_FACTOR

        protected static final int PATTERN_MATCH_RESULT_SCALE_FACTOR
        See Also:
        Constant Field Values

    • Constructor Detail

      • OneDReader

        public OneDReader()

    • Method Detail

      • decode

        public Result decode​(BinaryBitmap image,
                     java.util.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.
        Specified by:
        reset in interface Reader

      • 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

      • patternMatchVariance

        protected static int patternMatchVariance​(int[] counters,
                                          int[] pattern,
                                          int 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, where the ratio has been multiplied by 256. So, 0 means no variance (perfect match); 256 means the total variance between counters and patterns equals the pattern length, higher values mean even more variance

      • decodeRow

        public abstract Result decodeRow​(int rowNumber,
                                 BitArray row,
                                 java.util.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