moved java files for pre-convert

src/multi/ByQuadrantReader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi;
+
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.ChecksumException;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.FormatException;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.Reader;
+import com.google.zxing.Result;
+import com.google.zxing.ResultPoint;
+
+import java.util.Map;
+
+/**
+ * This class attempts to decode a barcode from an image, not by scanning the whole image,
+ * but by scanning subsets of the image. This is important when there may be multiple barcodes in
+ * an image, and detecting a barcode may find parts of multiple barcode and fail to decode
+ * (e.g. QR Codes). Instead this scans the four quadrants of the image -- and also the center
+ * 'quadrant' to cover the case where a barcode is found in the center.
+ *
+ * @see GenericMultipleBarcodeReader
+ */
+public final class ByQuadrantReader implements Reader {
+
+  private final Reader delegate;
+
+  public ByQuadrantReader(Reader delegate) {
+    this.delegate = delegate;
+  }
+
+  @Override
+  public Result decode(BinaryBitmap image)
+      throws NotFoundException, ChecksumException, FormatException {
+    return decode(image, null);
+  }
+
+  @Override
+  public Result decode(BinaryBitmap image, Map<DecodeHintType,?> hints)
+      throws NotFoundException, ChecksumException, FormatException {
+
+    int width = image.getWidth();
+    int height = image.getHeight();
+    int halfWidth = width / 2;
+    int halfHeight = height / 2;
+
+    try {
+      // No need to call makeAbsolute as results will be relative to original top left here
+      return delegate.decode(image.crop(0, 0, halfWidth, halfHeight), hints);
+    } catch (NotFoundException re) {
+      // continue
+    }
+
+    try {
+      Result result = delegate.decode(image.crop(halfWidth, 0, halfWidth, halfHeight), hints);
+      makeAbsolute(result.getResultPoints(), halfWidth, 0);
+      return result;
+    } catch (NotFoundException re) {
+      // continue
+    }
+
+    try {
+      Result result = delegate.decode(image.crop(0, halfHeight, halfWidth, halfHeight), hints);
+      makeAbsolute(result.getResultPoints(), 0, halfHeight);
+      return result;
+    } catch (NotFoundException re) {
+      // continue
+    }
+
+    try {
+      Result result = delegate.decode(image.crop(halfWidth, halfHeight, halfWidth, halfHeight), hints);
+      makeAbsolute(result.getResultPoints(), halfWidth, halfHeight);
+      return result;
+    } catch (NotFoundException re) {
+      // continue
+    }
+
+    int quarterWidth = halfWidth / 2;
+    int quarterHeight = halfHeight / 2;
+    BinaryBitmap center = image.crop(quarterWidth, quarterHeight, halfWidth, halfHeight);
+    Result result = delegate.decode(center, hints);
+    makeAbsolute(result.getResultPoints(), quarterWidth, quarterHeight);
+    return result;
+  }
+
+  @Override
+  public void reset() {
+    delegate.reset();
+  }
+
+  private static void makeAbsolute(ResultPoint[] points, int leftOffset, int topOffset) {
+    if (points != null) {
+      for (int i = 0; i < points.length; i++) {
+        ResultPoint relative = points[i];
+        if (relative != null) {
+          points[i] = new ResultPoint(relative.getX() + leftOffset, relative.getY() + topOffset);
+        }    
+      }
+    }
+  }
+
+}

src/multi/GenericMultipleBarcodeReader.java

@@ -0,0 +1,182 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi;
+
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.Reader;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.ResultPoint;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * <p>Attempts to locate multiple barcodes in an image by repeatedly decoding portion of the image.
+ * After one barcode is found, the areas left, above, right and below the barcode's
+ * {@link ResultPoint}s are scanned, recursively.</p>
+ *
+ * <p>A caller may want to also employ {@link ByQuadrantReader} when attempting to find multiple
+ * 2D barcodes, like QR Codes, in an image, where the presence of multiple barcodes might prevent
+ * detecting any one of them.</p>
+ *
+ * <p>That is, instead of passing a {@link Reader} a caller might pass
+ * {@code new ByQuadrantReader(reader)}.</p>
+ *
+ * @author Sean Owen
+ */
+public final class GenericMultipleBarcodeReader implements MultipleBarcodeReader {
+
+  private static final int MIN_DIMENSION_TO_RECUR = 100;
+  private static final int MAX_DEPTH = 4;
+
+  static final Result[] EMPTY_RESULT_ARRAY = new Result[0];
+
+  private final Reader delegate;
+
+  public GenericMultipleBarcodeReader(Reader delegate) {
+    this.delegate = delegate;
+  }
+
+  @Override
+  public Result[] decodeMultiple(BinaryBitmap image) throws NotFoundException {
+    return decodeMultiple(image, null);
+  }
+
+  @Override
+  public Result[] decodeMultiple(BinaryBitmap image, Map<DecodeHintType,?> hints)
+      throws NotFoundException {
+    List<Result> results = new ArrayList<>();
+    doDecodeMultiple(image, hints, results, 0, 0, 0);
+    if (results.isEmpty()) {
+      throw NotFoundException.getNotFoundInstance();
+    }
+    return results.toArray(EMPTY_RESULT_ARRAY);
+  }
+
+  private void doDecodeMultiple(BinaryBitmap image,
+                                Map<DecodeHintType,?> hints,
+                                List<Result> results,
+                                int xOffset,
+                                int yOffset,
+                                int currentDepth) {
+    if (currentDepth > MAX_DEPTH) {
+      return;
+    }
+
+    Result result;
+    try {
+      result = delegate.decode(image, hints);
+    } catch (ReaderException ignored) {
+      return;
+    }
+    boolean alreadyFound = false;
+    for (Result existingResult : results) {
+      if (existingResult.getText().equals(result.getText())) {
+        alreadyFound = true;
+        break;
+      }
+    }
+    if (!alreadyFound) {
+      results.add(translateResultPoints(result, xOffset, yOffset));
+    }
+    ResultPoint[] resultPoints = result.getResultPoints();
+    if (resultPoints == null || resultPoints.length == 0) {
+      return;
+    }
+    int width = image.getWidth();
+    int height = image.getHeight();
+    float minX = width;
+    float minY = height;
+    float maxX = 0.0f;
+    float maxY = 0.0f;
+    for (ResultPoint point : resultPoints) {
+      if (point == null) {
+        continue;
+      }
+      float x = point.getX();
+      float y = point.getY();
+      if (x < minX) {
+        minX = x;
+      }
+      if (y < minY) {
+        minY = y;
+      }
+      if (x > maxX) {
+        maxX = x;
+      }
+      if (y > maxY) {
+        maxY = y;
+      }
+    }
+
+    // Decode left of barcode
+    if (minX > MIN_DIMENSION_TO_RECUR) {
+      doDecodeMultiple(image.crop(0, 0, (int) minX, height),
+                       hints, results,
+                       xOffset, yOffset,
+                       currentDepth + 1);
+    }
+    // Decode above barcode
+    if (minY > MIN_DIMENSION_TO_RECUR) {
+      doDecodeMultiple(image.crop(0, 0, width, (int) minY),
+                       hints, results,
+                       xOffset, yOffset,
+                       currentDepth + 1);
+    }
+    // Decode right of barcode
+    if (maxX < width - MIN_DIMENSION_TO_RECUR) {
+      doDecodeMultiple(image.crop((int) maxX, 0, width - (int) maxX, height),
+                       hints, results,
+                       xOffset + (int) maxX, yOffset,
+                       currentDepth + 1);
+    }
+    // Decode below barcode
+    if (maxY < height - MIN_DIMENSION_TO_RECUR) {
+      doDecodeMultiple(image.crop(0, (int) maxY, width, height - (int) maxY),
+                       hints, results,
+                       xOffset, yOffset + (int) maxY,
+                       currentDepth + 1);
+    }
+  }
+
+  private static Result translateResultPoints(Result result, int xOffset, int yOffset) {
+    ResultPoint[] oldResultPoints = result.getResultPoints();
+    if (oldResultPoints == null) {
+      return result;
+    }
+    ResultPoint[] newResultPoints = new ResultPoint[oldResultPoints.length];
+    for (int i = 0; i < oldResultPoints.length; i++) {
+      ResultPoint oldPoint = oldResultPoints[i];
+      if (oldPoint != null) {
+        newResultPoints[i] = new ResultPoint(oldPoint.getX() + xOffset, oldPoint.getY() + yOffset);
+      }
+    }
+    Result newResult = new Result(result.getText(),
+                                  result.getRawBytes(),
+                                  result.getNumBits(),
+                                  newResultPoints,
+                                  result.getBarcodeFormat(),
+                                  result.getTimestamp());
+    newResult.putAllMetadata(result.getResultMetadata());
+    return newResult;
+  }
+
+}

src/multi/MultipleBarcodeReader.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi;
+
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.Result;
+
+import java.util.Map;
+
+/**
+ * Implementation of this interface attempt to read several barcodes from one image.
+ *
+ * @see com.google.zxing.Reader
+ * @author Sean Owen
+ */
+public interface MultipleBarcodeReader {
+
+  Result[] decodeMultiple(BinaryBitmap image) throws NotFoundException;
+
+  Result[] decodeMultiple(BinaryBitmap image,
+                          Map<DecodeHintType,?> hints) throws NotFoundException;
+
+}

src/multi/qrcode/QRCodeMultiReader.java

@@ -0,0 +1,149 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi.qrcode;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.ResultMetadataType;
+import com.google.zxing.ResultPoint;
+import com.google.zxing.common.DecoderResult;
+import com.google.zxing.common.DetectorResult;
+import com.google.zxing.multi.MultipleBarcodeReader;
+import com.google.zxing.multi.qrcode.detector.MultiDetector;
+import com.google.zxing.qrcode.QRCodeReader;
+import com.google.zxing.qrcode.decoder.QRCodeDecoderMetaData;
+
+import java.io.ByteArrayOutputStream;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Collections;
+import java.util.Comparator;
+
+/**
+ * This implementation can detect and decode multiple QR Codes in an image.
+ *
+ * @author Sean Owen
+ * @author Hannes Erven
+ */
+public final class QRCodeMultiReader extends QRCodeReader implements MultipleBarcodeReader {
+
+  private static final Result[] EMPTY_RESULT_ARRAY = new Result[0];
+  private static final ResultPoint[] NO_POINTS = new ResultPoint[0];
+
+  @Override
+  public Result[] decodeMultiple(BinaryBitmap image) throws NotFoundException {
+    return decodeMultiple(image, null);
+  }
+
+  @Override
+  public Result[] decodeMultiple(BinaryBitmap image, Map<DecodeHintType,?> hints) throws NotFoundException {
+    List<Result> results = new ArrayList<>();
+    DetectorResult[] detectorResults = new MultiDetector(image.getBlackMatrix()).detectMulti(hints);
+    for (DetectorResult detectorResult : detectorResults) {
+      try {
+        DecoderResult decoderResult = getDecoder().decode(detectorResult.getBits(), hints);
+        ResultPoint[] points = detectorResult.getPoints();
+        // If the code was mirrored: swap the bottom-left and the top-right points.
+        if (decoderResult.getOther() instanceof QRCodeDecoderMetaData) {
+          ((QRCodeDecoderMetaData) decoderResult.getOther()).applyMirroredCorrection(points);
+        }
+        Result result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), points,
+                                   BarcodeFormat.QR_CODE);
+        List<byte[]> byteSegments = decoderResult.getByteSegments();
+        if (byteSegments != null) {
+          result.putMetadata(ResultMetadataType.BYTE_SEGMENTS, byteSegments);
+        }
+        String ecLevel = decoderResult.getECLevel();
+        if (ecLevel != null) {
+          result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, ecLevel);
+        }
+        if (decoderResult.hasStructuredAppend()) {
+          result.putMetadata(ResultMetadataType.STRUCTURED_APPEND_SEQUENCE,
+                             decoderResult.getStructuredAppendSequenceNumber());
+          result.putMetadata(ResultMetadataType.STRUCTURED_APPEND_PARITY,
+                             decoderResult.getStructuredAppendParity());
+        }
+        results.add(result);
+      } catch (ReaderException re) {
+        // ignore and continue
+      }
+    }
+    if (results.isEmpty()) {
+      return EMPTY_RESULT_ARRAY;
+    } else {
+      results = processStructuredAppend(results);
+      return results.toArray(EMPTY_RESULT_ARRAY);
+    }
+  }
+
+  static List<Result> processStructuredAppend(List<Result> results) {
+    List<Result> newResults = new ArrayList<>();
+    List<Result> saResults = new ArrayList<>();
+    for (Result result : results) {
+      if (result.getResultMetadata().containsKey(ResultMetadataType.STRUCTURED_APPEND_SEQUENCE)) {
+        saResults.add(result);
+      } else {
+        newResults.add(result);
+      }
+    }
+    if (saResults.isEmpty()) {
+      return results;
+    }
+
+    // sort and concatenate the SA list items
+    Collections.sort(saResults, new SAComparator());
+    StringBuilder newText = new StringBuilder();
+    ByteArrayOutputStream newRawBytes = new ByteArrayOutputStream();
+    ByteArrayOutputStream newByteSegment = new ByteArrayOutputStream();
+    for (Result saResult : saResults) {
+      newText.append(saResult.getText());
+      byte[] saBytes = saResult.getRawBytes();
+      newRawBytes.write(saBytes, 0, saBytes.length);
+      @SuppressWarnings("unchecked")
+      Iterable<byte[]> byteSegments =
+          (Iterable<byte[]>) saResult.getResultMetadata().get(ResultMetadataType.BYTE_SEGMENTS);
+      if (byteSegments != null) {
+        for (byte[] segment : byteSegments) {
+          newByteSegment.write(segment, 0, segment.length);
+        }
+      }
+    }
+
+    Result newResult = new Result(newText.toString(), newRawBytes.toByteArray(), NO_POINTS, BarcodeFormat.QR_CODE);
+    if (newByteSegment.size() > 0) {
+      newResult.putMetadata(ResultMetadataType.BYTE_SEGMENTS, Collections.singletonList(newByteSegment.toByteArray()));
+    }
+    newResults.add(newResult);
+    return newResults;
+  }
+
+  private static final class SAComparator implements Comparator<Result>, Serializable {
+    @Override
+    public int compare(Result a, Result b) {
+      int aNumber = (int) a.getResultMetadata().get(ResultMetadataType.STRUCTURED_APPEND_SEQUENCE);
+      int bNumber = (int) b.getResultMetadata().get(ResultMetadataType.STRUCTURED_APPEND_SEQUENCE);
+      return Integer.compare(aNumber, bNumber);
+    }
+  }
+
+}

src/multi/qrcode/detector/MultiDetector.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi.qrcode.detector;
+
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.ReaderException;
+import com.google.zxing.ResultPointCallback;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.common.DetectorResult;
+import com.google.zxing.qrcode.detector.Detector;
+import com.google.zxing.qrcode.detector.FinderPatternInfo;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * <p>Encapsulates logic that can detect one or more QR Codes in an image, even if the QR Code
+ * is rotated or skewed, or partially obscured.</p>
+ *
+ * @author Sean Owen
+ * @author Hannes Erven
+ */
+public final class MultiDetector extends Detector {
+
+  private static final DetectorResult[] EMPTY_DETECTOR_RESULTS = new DetectorResult[0];
+
+  public MultiDetector(BitMatrix image) {
+    super(image);
+  }
+
+  public DetectorResult[] detectMulti(Map<DecodeHintType,?> hints) throws NotFoundException {
+    BitMatrix image = getImage();
+    ResultPointCallback resultPointCallback =
+        hints == null ? null : (ResultPointCallback) hints.get(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
+    MultiFinderPatternFinder finder = new MultiFinderPatternFinder(image, resultPointCallback);
+    FinderPatternInfo[] infos = finder.findMulti(hints);
+
+    if (infos.length == 0) {
+      throw NotFoundException.getNotFoundInstance();
+    }
+
+    List<DetectorResult> result = new ArrayList<>();
+    for (FinderPatternInfo info : infos) {
+      try {
+        result.add(processFinderPatternInfo(info));
+      } catch (ReaderException e) {
+        // ignore
+      }
+    }
+    if (result.isEmpty()) {
+      return EMPTY_DETECTOR_RESULTS;
+    } else {
+      return result.toArray(EMPTY_DETECTOR_RESULTS);
+    }
+  }
+
+}

src/multi/qrcode/detector/MultiFinderPatternFinder.java

@@ -0,0 +1,290 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.zxing.multi.qrcode.detector;
+
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.NotFoundException;
+import com.google.zxing.ResultPoint;
+import com.google.zxing.ResultPointCallback;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.qrcode.detector.FinderPattern;
+import com.google.zxing.qrcode.detector.FinderPatternFinder;
+import com.google.zxing.qrcode.detector.FinderPatternInfo;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * <p>This class attempts to find finder patterns in a QR Code. Finder patterns are the square
+ * markers at three corners of a QR Code.</p>
+ *
+ * <p>This class is thread-safe but not reentrant. Each thread must allocate its own object.
+ *
+ * <p>In contrast to {@link FinderPatternFinder}, this class will return an array of all possible
+ * QR code locations in the image.</p>
+ *
+ * <p>Use the TRY_HARDER hint to ask for a more thorough detection.</p>
+ *
+ * @author Sean Owen
+ * @author Hannes Erven
+ */
+public final class MultiFinderPatternFinder extends FinderPatternFinder {
+
+  private static final FinderPatternInfo[] EMPTY_RESULT_ARRAY = new FinderPatternInfo[0];
+  private static final FinderPattern[] EMPTY_FP_ARRAY = new FinderPattern[0];
+  private static final FinderPattern[][] EMPTY_FP_2D_ARRAY = new FinderPattern[0][];
+
+  // TODO MIN_MODULE_COUNT and MAX_MODULE_COUNT would be great hints to ask the user for
+  // since it limits the number of regions to decode
+
+  // max. legal count of modules per QR code edge (177)
+  private static final float MAX_MODULE_COUNT_PER_EDGE = 180;
+  // min. legal count per modules per QR code edge (11)
+  private static final float MIN_MODULE_COUNT_PER_EDGE = 9;
+
+  /**
+   * More or less arbitrary cutoff point for determining if two finder patterns might belong
+   * to the same code if they differ less than DIFF_MODSIZE_CUTOFF_PERCENT percent in their
+   * estimated modules sizes.
+   */
+  private static final float DIFF_MODSIZE_CUTOFF_PERCENT = 0.05f;
+
+  /**
+   * More or less arbitrary cutoff point for determining if two finder patterns might belong
+   * to the same code if they differ less than DIFF_MODSIZE_CUTOFF pixels/module in their
+   * estimated modules sizes.
+   */
+  private static final float DIFF_MODSIZE_CUTOFF = 0.5f;
+
+
+  /**
+   * A comparator that orders FinderPatterns by their estimated module size.
+   */
+  private static final class ModuleSizeComparator implements Comparator<FinderPattern>, Serializable {
+    @Override
+    public int compare(FinderPattern center1, FinderPattern center2) {
+      float value = center2.getEstimatedModuleSize() - center1.getEstimatedModuleSize();
+      return value < 0.0 ? -1 : value > 0.0 ? 1 : 0;
+    }
+  }
+
+  public MultiFinderPatternFinder(BitMatrix image, ResultPointCallback resultPointCallback) {
+    super(image, resultPointCallback);
+  }
+
+  /**
+   * @return the 3 best {@link FinderPattern}s from our list of candidates. The "best" are
+   *         those that have been detected at least 2 times, and whose module
+   *         size differs from the average among those patterns the least
+   * @throws NotFoundException if 3 such finder patterns do not exist
+   */
+  private FinderPattern[][] selectMultipleBestPatterns() throws NotFoundException {
+    List<FinderPattern> possibleCenters = new ArrayList<>();
+    for (FinderPattern fp : getPossibleCenters()) {
+      if (fp.getCount() >= 2) {
+        possibleCenters.add(fp);
+      }
+    }
+    int size = possibleCenters.size();
+
+    if (size < 3) {
+      // Couldn't find enough finder patterns
+      throw NotFoundException.getNotFoundInstance();
+    }
+
+    /*
+     * Begin HE modifications to safely detect multiple codes of equal size
+     */
+    if (size == 3) {
+      return new FinderPattern[][] { possibleCenters.toArray(EMPTY_FP_ARRAY) };
+    }
+
+    // Sort by estimated module size to speed up the upcoming checks
+    Collections.sort(possibleCenters, new ModuleSizeComparator());
+
+    /*
+     * Now lets start: build a list of tuples of three finder locations that
+     *  - feature similar module sizes
+     *  - are placed in a distance so the estimated module count is within the QR specification
+     *  - have similar distance between upper left/right and left top/bottom finder patterns
+     *  - form a triangle with 90° angle (checked by comparing top right/bottom left distance
+     *    with pythagoras)
+     *
+     * Note: we allow each point to be used for more than one code region: this might seem
+     * counterintuitive at first, but the performance penalty is not that big. At this point,
+     * we cannot make a good quality decision whether the three finders actually represent
+     * a QR code, or are just by chance laid out so it looks like there might be a QR code there.
+     * So, if the layout seems right, lets have the decoder try to decode.
+     */
+
+    List<FinderPattern[]> results = new ArrayList<>(); // holder for the results
+
+    for (int i1 = 0; i1 < (size - 2); i1++) {
+      FinderPattern p1 = possibleCenters.get(i1);
+      if (p1 == null) {
+        continue;
+      }
+
+      for (int i2 = i1 + 1; i2 < (size - 1); i2++) {
+        FinderPattern p2 = possibleCenters.get(i2);
+        if (p2 == null) {
+          continue;
+        }
+
+        // Compare the expected module sizes; if they are really off, skip
+        float vModSize12 = (p1.getEstimatedModuleSize() - p2.getEstimatedModuleSize()) /
+            Math.min(p1.getEstimatedModuleSize(), p2.getEstimatedModuleSize());
+        float vModSize12A = Math.abs(p1.getEstimatedModuleSize() - p2.getEstimatedModuleSize());
+        if (vModSize12A > DIFF_MODSIZE_CUTOFF && vModSize12 >= DIFF_MODSIZE_CUTOFF_PERCENT) {
+          // break, since elements are ordered by the module size deviation there cannot be
+          // any more interesting elements for the given p1.
+          break;
+        }
+
+        for (int i3 = i2 + 1; i3 < size; i3++) {
+          FinderPattern p3 = possibleCenters.get(i3);
+          if (p3 == null) {
+            continue;
+          }
+
+          // Compare the expected module sizes; if they are really off, skip
+          float vModSize23 = (p2.getEstimatedModuleSize() - p3.getEstimatedModuleSize()) /
+              Math.min(p2.getEstimatedModuleSize(), p3.getEstimatedModuleSize());
+          float vModSize23A = Math.abs(p2.getEstimatedModuleSize() - p3.getEstimatedModuleSize());
+          if (vModSize23A > DIFF_MODSIZE_CUTOFF && vModSize23 >= DIFF_MODSIZE_CUTOFF_PERCENT) {
+            // break, since elements are ordered by the module size deviation there cannot be
+            // any more interesting elements for the given p1.
+            break;
+          }
+
+          FinderPattern[] test = {p1, p2, p3};
+          ResultPoint.orderBestPatterns(test);
+
+          // Calculate the distances: a = topleft-bottomleft, b=topleft-topright, c = diagonal
+          FinderPatternInfo info = new FinderPatternInfo(test);
+          float dA = ResultPoint.distance(info.getTopLeft(), info.getBottomLeft());
+          float dC = ResultPoint.distance(info.getTopRight(), info.getBottomLeft());
+          float dB = ResultPoint.distance(info.getTopLeft(), info.getTopRight());
+
+          // Check the sizes
+          float estimatedModuleCount = (dA + dB) / (p1.getEstimatedModuleSize() * 2.0f);
+          if (estimatedModuleCount > MAX_MODULE_COUNT_PER_EDGE ||
+              estimatedModuleCount < MIN_MODULE_COUNT_PER_EDGE) {
+            continue;
+          }
+
+          // Calculate the difference of the edge lengths in percent
+          float vABBC = Math.abs((dA - dB) / Math.min(dA, dB));
+          if (vABBC >= 0.1f) {
+            continue;
+          }
+
+          // Calculate the diagonal length by assuming a 90° angle at topleft
+          float dCpy = (float) Math.sqrt((double) dA * dA + (double) dB * dB);
+          // Compare to the real distance in %
+          float vPyC = Math.abs((dC - dCpy) / Math.min(dC, dCpy));
+
+          if (vPyC >= 0.1f) {
+            continue;
+          }
+
+          // All tests passed!
+          results.add(test);
+        }
+      }
+    }
+
+    if (!results.isEmpty()) {
+      return results.toArray(EMPTY_FP_2D_ARRAY);
+    }
+
+    // Nothing found!
+    throw NotFoundException.getNotFoundInstance();
+  }
+
+  public FinderPatternInfo[] findMulti(Map<DecodeHintType,?> hints) throws NotFoundException {
+    boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
+    BitMatrix image = getImage();
+    int maxI = image.getHeight();
+    int maxJ = image.getWidth();
+    // We are looking for black/white/black/white/black modules in
+    // 1:1:3:1:1 ratio; this tracks the number of such modules seen so far
+
+    // Let's assume that the maximum version QR Code we support takes up 1/4 the height of the
+    // image, and then account for the center being 3 modules in size. This gives the smallest
+    // number of pixels the center could be, so skip this often. When trying harder, look for all
+    // QR versions regardless of how dense they are.
+    int iSkip = (3 * maxI) / (4 * MAX_MODULES);
+    if (iSkip < MIN_SKIP || tryHarder) {
+      iSkip = MIN_SKIP;
+    }
+
+    int[] stateCount = new int[5];
+    for (int i = iSkip - 1; i < maxI; i += iSkip) {
+      // Get a row of black/white values
+      doClearCounts(stateCount);
+      int currentState = 0;
+      for (int j = 0; j < maxJ; j++) {
+        if (image.get(j, i)) {
+          // Black pixel
+          if ((currentState & 1) == 1) { // Counting white pixels
+            currentState++;
+          }
+          stateCount[currentState]++;
+        } else { // White pixel
+          if ((currentState & 1) == 0) { // Counting black pixels
+            if (currentState == 4) { // A winner?
+              if (foundPatternCross(stateCount) && handlePossibleCenter(stateCount, i, j)) { // Yes
+                // Clear state to start looking again
+                currentState = 0;
+                doClearCounts(stateCount);
+              } else { // No, shift counts back by two
+                doShiftCounts2(stateCount);
+                currentState = 3;
+              }
+            } else {
+              stateCount[++currentState]++;
+            }
+          } else { // Counting white pixels
+            stateCount[currentState]++;
+          }
+        }
+      } // for j=...
+
+      if (foundPatternCross(stateCount)) {
+        handlePossibleCenter(stateCount, i, maxJ);
+      }
+    } // for i=iSkip-1 ...
+    FinderPattern[][] patternInfo = selectMultipleBestPatterns();
+    List<FinderPatternInfo> result = new ArrayList<>();
+    for (FinderPattern[] pattern : patternInfo) {
+      ResultPoint.orderBestPatterns(pattern);
+      result.add(new FinderPatternInfo(pattern));
+    }
+
+    if (result.isEmpty()) {
+      return EMPTY_RESULT_ARRAY;
+    } else {
+      return result.toArray(EMPTY_RESULT_ARRAY);
+    }
+  }
+
+}