1 files changed, 156 insertions, 0 deletions
diff --git a/libraries/zxing/src/com/google/zxing/multi/GenericMultipleBarcodeReader.java b/libraries/zxing/src/com/google/zxing/multi/GenericMultipleBarcodeReader.java
new file mode 100644
index 000000000..70d454251
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+++ b/libraries/zxing/src/com/google/zxing/multi/GenericMultipleBarcodeReader.java
@@ -0,0 +1,156 @@
+/*
+ * 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.NotFoundException;
+import com.google.zxing.Reader;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.ResultPoint;
+
+import java.util.Hashtable;
+import java.util.Vector;
+
+/**
+ * <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 com.google.zxing.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)</code>.</p>
+ *
+ * @author Sean Owen
+ */
+public final class GenericMultipleBarcodeReader implements MultipleBarcodeReader {
+
+  private static final int MIN_DIMENSION_TO_RECUR = 100;
+
+  private final Reader delegate;
+
+  public GenericMultipleBarcodeReader(Reader delegate) {
+    this.delegate = delegate;
+  }
+
+  public Result[] decodeMultiple(BinaryBitmap image) throws NotFoundException {
+    return decodeMultiple(image, null);
+  }
+
+  public Result[] decodeMultiple(BinaryBitmap image, Hashtable hints)
+      throws NotFoundException {
+    Vector results = new Vector();
+    doDecodeMultiple(image, hints, results, 0, 0);
+    if (results.isEmpty()) {
+      throw NotFoundException.getNotFoundInstance();
+    }
+    int numResults = results.size();
+    Result[] resultArray = new Result[numResults];
+    for (int i = 0; i < numResults; i++) {
+      resultArray[i] = (Result) results.elementAt(i);
+    }
+    return resultArray;
+  }
+
+  private void doDecodeMultiple(BinaryBitmap image,
+                                Hashtable hints,
+                                Vector results,
+                                int xOffset,
+                                int yOffset) {
+    Result result;
+    try {
+      result = delegate.decode(image, hints);
+    } catch (ReaderException re) {
+      return;
+    }
+    boolean alreadyFound = false;
+    for (int i = 0; i < results.size(); i++) {
+      Result existingResult = (Result) results.elementAt(i);
+      if (existingResult.getText().equals(result.getText())) {
+        alreadyFound = true;
+        break;
+      }
+    }
+    if (alreadyFound) {
+      return;
+    }
+    results.addElement(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 (int i = 0; i < resultPoints.length; i++) {
+      ResultPoint point = resultPoints[i];
+      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);
+    }
+    // Decode above barcode
+    if (minY > MIN_DIMENSION_TO_RECUR) {
+      doDecodeMultiple(image.crop(0, 0, width, (int) minY),
+                       hints, results, xOffset, yOffset);
+    }
+    // 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);
+    }
+    // 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);
+    }
+  }
+
+  private static Result translateResultPoints(Result result, int xOffset, int yOffset) {
+    ResultPoint[] oldResultPoints = result.getResultPoints();
+    ResultPoint[] newResultPoints = new ResultPoint[oldResultPoints.length];
+    for (int i = 0; i < oldResultPoints.length; i++) {
+      ResultPoint oldPoint = oldResultPoints[i];
+      newResultPoints[i] = new ResultPoint(oldPoint.getX() + xOffset, oldPoint.getY() + yOffset);
+    }
+    return new Result(result.getText(), result.getRawBytes(), newResultPoints,
+        result.getBarcodeFormat());
+  }
+
+}