Java Code Examples for com.google.zxing.BinaryBitmap#getBlackRow()

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  int middle = height / 2;
  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  int middle = height / 2;
  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  int middle = height / 2;
  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  int middle = height >> 1;
  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  int middle = height >> 1;
  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  int middle = height >> 1;
  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  int middle = height >> 1;
  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) / 2;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException ignored) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching alternately above and below the
 * middle, and farther out each time. rowStep is the number of rows between each successive
 * attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc.
 * rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
 * image if "trying harder".
 *
 * @param image The image to decode
 * @param hints Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image,
                        Map<DecodeHintType,?> hints) throws NotFoundException {
  int width = image.getWidth();
  int height = image.getHeight();
  BitArray row = new BitArray(width);

  int middle = height >> 1;
  boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
  int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
  int maxLines;
  if (tryHarder) {
    maxLines = height; // Look at the whole image, not just the center
  } else {
    maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle half of the image
  }

  for (int x = 0; x < maxLines; x++) {

    // Scanning from the middle out. Determine which row we're looking at next:
    int rowStepsAboveOrBelow = (x + 1) >> 1;
    boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
    int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
    if (rowNumber < 0 || rowNumber >= height) {
      // Oops, if we run off the top or bottom, stop
      break;
    }

    // Estimate black point for this row and load it:
    try {
      row = image.getBlackRow(rowNumber, row);
    } catch (NotFoundException nfe) {
      continue;
    }

    // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
    // handle decoding upside down barcodes.
    for (int attempt = 0; attempt < 2; attempt++) {
      if (attempt == 1) { // trying again?
        row.reverse(); // reverse the row and continue
        // This means we will only ever draw result points *once* in the life of this method
        // since we want to avoid drawing the wrong points after flipping the row, and,
        // don't want to clutter with noise from every single row scan -- just the scans
        // that start on the center line.
        if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
          Map<DecodeHintType,Object> newHints = new EnumMap<DecodeHintType,Object>(DecodeHintType.class);
          newHints.putAll(hints);
          newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
          hints = newHints;
        }
      }
      try {
        // Look for a barcode
        Result result = decodeRow(rowNumber, row, hints);
        // We found our barcode
        if (attempt == 1) {
          // But it was upside down, so note that
          result.putMetadata(ResultMetadataType.ORIENTATION, 180);
          // And remember to flip the result points horizontally.
          ResultPoint[] points = result.getResultPoints();
          if (points != null) {
            points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
            points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
          }
        }
        return result;
      } catch (ReaderException re) {
        // continue -- just couldn't decode this row
      }
    }
  }

  throw NotFoundException.getNotFoundInstance();
}
 

/**
 * We're going to examine rows from the middle outward, searching
 * alternately above and below the middle, and farther out each time.
 * rowStep is the number of rows between each successive attempt above and
 * below the middle. So we'd scan row middle, then middle - rowStep, then
 * middle + rowStep, then middle - (2 * rowStep), etc. rowStep is bigger as
 * the image is taller, but is always at least 1. We've somewhat arbitrarily
 * decided that moving up and down by about 1/16 of the image is pretty
 * good; we try more of the image if "trying harder".
 * 
 * @param image
 *            The image to decode
 * @param hints
 *            Any hints that were requested
 * @return The contents of the decoded barcode
 * @throws NotFoundException
 *             Any spontaneous errors which occur
 */
private Result doDecode(BinaryBitmap image, Map<DecodeHintType, ?> hints) throws NotFoundException {
	int width = image.getWidth();
	int height = image.getHeight();
	BitArray row = new BitArray(width);

	int middle = height >> 1;
	boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
	int rowStep = Math.max(1, height >> (tryHarder ? 8 : 5));
	int maxLines;
	if (tryHarder) {
		maxLines = height; // Look at the whole image, not just the center
	} else {
		maxLines = 15; // 15 rows spaced 1/32 apart is roughly the middle
						// half of the image
	}

	for (int x = 0; x < maxLines; x++) {

		// Scanning from the middle out. Determine which row we're looking
		// at next:
		int rowStepsAboveOrBelow = (x + 1) / 2;
		boolean isAbove = (x & 0x01) == 0; // i.e. is x even?
		int rowNumber = middle + rowStep * (isAbove ? rowStepsAboveOrBelow : -rowStepsAboveOrBelow);
		if (rowNumber < 0 || rowNumber >= height) {
			// Oops, if we run off the top or bottom, stop
			break;
		}

		// Estimate black point for this row and load it:
		try {
			row = image.getBlackRow(rowNumber, row);
		} catch (NotFoundException ignored) {
			continue;
		}

		// While we have the image data in a BitArray, it's fairly cheap to
		// reverse it in place to
		// handle decoding upside down barcodes.
		for (int attempt = 0; attempt < 2; attempt++) {
			if (attempt == 1) { // trying again?
				row.reverse(); // reverse the row and continue
				// This means we will only ever draw result points *once* in
				// the life of this method
				// since we want to avoid drawing the wrong points after
				// flipping the row, and,
				// don't want to clutter with noise from every single row
				// scan -- just the scans
				// that start on the center line.
				if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
					Map<DecodeHintType, Object> newHints = new EnumMap<>(DecodeHintType.class);
					newHints.putAll(hints);
					newHints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
					hints = newHints;
				}
			}
			try {
				// Look for a barcode
				Result result = decodeRow(rowNumber, row, hints);
				// We found our barcode
				if (attempt == 1) {
					// But it was upside down, so note that
					result.putMetadata(ResultMetadataType.ORIENTATION, 180);
					// And remember to flip the result points horizontally.
					ResultPoint[] points = result.getResultPoints();
					if (points != null) {
						points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
						points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
					}
				}
				return result;
			} catch (ReaderException re) {
				// continue -- just couldn't decode this row
			}
		}
	}

	throw NotFoundException.getNotFoundInstance();
}