Class PDF417ScanningDecoder

java.lang.Object
com.google.zxing.pdf417.decoder.PDF417ScanningDecoder
public final class PDF417ScanningDecoder extends Object

  • Field Details

  • Constructor Details

    • PDF417ScanningDecoder

      private PDF417ScanningDecoder()

  • Method Details

    • decode

      public static DecoderResult decode(BitMatrix image, ResultPoint imageTopLeft, ResultPoint imageBottomLeft, ResultPoint imageTopRight, ResultPoint imageBottomRight, int minCodewordWidth, int maxCodewordWidth) throws NotFoundException, FormatException, ChecksumException
      Throws:
      NotFoundException
      FormatException
      ChecksumException

    • merge

      private static DetectionResult merge(DetectionResultRowIndicatorColumn leftRowIndicatorColumn, DetectionResultRowIndicatorColumn rightRowIndicatorColumn) throws NotFoundException
      Throws:
      NotFoundException

    • adjustBoundingBox

      private static BoundingBox adjustBoundingBox(DetectionResultRowIndicatorColumn rowIndicatorColumn) throws NotFoundException
      Throws:
      NotFoundException

    • getMax

      private static int getMax(int[] values)

    • getBarcodeMetadata

      private static BarcodeMetadata getBarcodeMetadata(DetectionResultRowIndicatorColumn leftRowIndicatorColumn, DetectionResultRowIndicatorColumn rightRowIndicatorColumn)

    • getRowIndicatorColumn

      private static DetectionResultRowIndicatorColumn getRowIndicatorColumn(BitMatrix image, BoundingBox boundingBox, ResultPoint startPoint, boolean leftToRight, int minCodewordWidth, int maxCodewordWidth)

    • adjustCodewordCount

      private static void adjustCodewordCount(DetectionResult detectionResult, BarcodeValue[][] barcodeMatrix) throws NotFoundException
      Throws:
      NotFoundException

    • createDecoderResult

      private static DecoderResult createDecoderResult(DetectionResult detectionResult) throws FormatException, ChecksumException, NotFoundException
      Throws:
      FormatException
      ChecksumException
      NotFoundException

    • createDecoderResultFromAmbiguousValues

      private static DecoderResult createDecoderResultFromAmbiguousValues(int ecLevel, int[] codewords, int[] erasureArray, int[] ambiguousIndexes, int[][] ambiguousIndexValues) throws FormatException, ChecksumException
      This method deals with the fact, that the decoding process doesn't always yield a single most likely value. The current error correction implementation doesn't deal with erasures very well, so it's better to provide a value for these ambiguous codewords instead of treating it as an erasure. The problem is that we don't know which of the ambiguous values to choose. We try decode using the first value, and if that fails, we use another of the ambiguous values and try to decode again. This usually only happens on very hard to read and decode barcodes, so decoding the normal barcodes is not affected by this.
      Parameters:
      erasureArray - contains the indexes of erasures
      ambiguousIndexes - array with the indexes that have more than one most likely value
      ambiguousIndexValues - two dimensional array that contains the ambiguous values. The first dimension must be the same length as the ambiguousIndexes array
      Throws:
      FormatException
      ChecksumException

    • createBarcodeMatrix

      private static BarcodeValue[][] createBarcodeMatrix(DetectionResult detectionResult)

    • isValidBarcodeColumn

      private static boolean isValidBarcodeColumn(DetectionResult detectionResult, int barcodeColumn)

    • getStartColumn

      private static int getStartColumn(DetectionResult detectionResult, int barcodeColumn, int imageRow, boolean leftToRight)

    • detectCodeword

      private static Codeword detectCodeword(BitMatrix image, int minColumn, int maxColumn, boolean leftToRight, int startColumn, int imageRow, int minCodewordWidth, int maxCodewordWidth)

    • getModuleBitCount

      private static int[] getModuleBitCount(BitMatrix image, int minColumn, int maxColumn, boolean leftToRight, int startColumn, int imageRow)

    • getNumberOfECCodeWords

      private static int getNumberOfECCodeWords(int barcodeECLevel)

    • adjustCodewordStartColumn

      private static int adjustCodewordStartColumn(BitMatrix image, int minColumn, int maxColumn, boolean leftToRight, int codewordStartColumn, int imageRow)

    • checkCodewordSkew

      private static boolean checkCodewordSkew(int codewordSize, int minCodewordWidth, int maxCodewordWidth)

    • decodeCodewords

      private static DecoderResult decodeCodewords(int[] codewords, int ecLevel, int[] erasures) throws FormatException, ChecksumException
      Throws:
      FormatException
      ChecksumException

    • correctErrors

      private static int correctErrors(int[] codewords, int[] erasures, int numECCodewords) throws ChecksumException

      Given data and error-correction codewords received, possibly corrupted by errors, attempts to correct the errors in-place.

      Parameters:
      codewords - data and error correction codewords
      erasures - positions of any known erasures
      numECCodewords - number of error correction codewords that are available in codewords
      Throws:
      ChecksumException - if error correction fails

    • verifyCodewordCount

      private static void verifyCodewordCount(int[] codewords, int numECCodewords) throws FormatException
      Verify that all is OK with the codeword array.
      Throws:
      FormatException

    • getBitCountForCodeword

      private static int[] getBitCountForCodeword(int codeword)

    • getCodewordBucketNumber

      private static int getCodewordBucketNumber(int codeword)

    • getCodewordBucketNumber

      private static int getCodewordBucketNumber(int[] moduleBitCount)

    • toString

      public static String toString(BarcodeValue[][] barcodeMatrix)