예제 #1
0
  /**
   * @param bitMatrix {@link BitMatrix} to parse
   * @throws FormatException if dimension is < 8 or > 144 or not 0 mod 2
   */
  BitMatrixParser(BitMatrix bitMatrix) throws FormatException {
    int dimension = bitMatrix.getHeight();
    if (dimension < 8 || dimension > 144 || (dimension & 0x01) != 0) {
      throw FormatException.getFormatInstance();
    }

    version = readVersion(bitMatrix);
    this.mappingBitMatrix = extractDataRegion(bitMatrix);
    this.readMappingMatrix =
        new BitMatrix(this.mappingBitMatrix.getWidth(), this.mappingBitMatrix.getHeight());
  }
예제 #2
0
  /**
   * Reads the bits in the {@link BitMatrix} representing the mapping matrix (No alignment patterns)
   * in the correct order in order to reconstitute the codewords bytes contained within the Data
   * Matrix Code.
   *
   * @return bytes encoded within the Data Matrix Code
   * @throws FormatException if the exact number of bytes expected is not read
   */
  byte[] readCodewords() throws FormatException {

    byte[] result = new byte[version.getTotalCodewords()];
    int resultOffset = 0;

    int row = 4;
    int column = 0;

    int numRows = mappingBitMatrix.getHeight();
    int numColumns = mappingBitMatrix.getWidth();

    boolean corner1Read = false;
    boolean corner2Read = false;
    boolean corner3Read = false;
    boolean corner4Read = false;

    // Read all of the codewords
    do {
      // Check the four corner cases
      if ((row == numRows) && (column == 0) && !corner1Read) {
        result[resultOffset++] = (byte) readCorner1(numRows, numColumns);
        row -= 2;
        column += 2;
        corner1Read = true;
      } else if ((row == numRows - 2)
          && (column == 0)
          && ((numColumns & 0x03) != 0)
          && !corner2Read) {
        result[resultOffset++] = (byte) readCorner2(numRows, numColumns);
        row -= 2;
        column += 2;
        corner2Read = true;
      } else if ((row == numRows + 4)
          && (column == 2)
          && ((numColumns & 0x07) == 0)
          && !corner3Read) {
        result[resultOffset++] = (byte) readCorner3(numRows, numColumns);
        row -= 2;
        column += 2;
        corner3Read = true;
      } else if ((row == numRows - 2)
          && (column == 0)
          && ((numColumns & 0x07) == 4)
          && !corner4Read) {
        result[resultOffset++] = (byte) readCorner4(numRows, numColumns);
        row -= 2;
        column += 2;
        corner4Read = true;
      } else {
        // Sweep upward diagonally to the right
        do {
          if ((row < numRows) && (column >= 0) && !readMappingMatrix.get(column, row)) {
            result[resultOffset++] = (byte) readUtah(row, column, numRows, numColumns);
          }
          row -= 2;
          column += 2;
        } while ((row >= 0) && (column < numColumns));
        row += 1;
        column += 3;

        // Sweep downward diagonally to the left
        do {
          if ((row >= 0) && (column < numColumns) && !readMappingMatrix.get(column, row)) {
            result[resultOffset++] = (byte) readUtah(row, column, numRows, numColumns);
          }
          row += 2;
          column -= 2;
        } while ((row < numRows) && (column >= 0));
        row += 3;
        column += 1;
      }
    } while ((row < numRows) || (column < numColumns));

    if (resultOffset != version.getTotalCodewords()) {
      throw FormatException.getFormatInstance();
    }
    return result;
  }