More PDF417 changes from Guenther

git-svn-id: https://zxing.googlecode.com/svn/trunk@2708 59b500cc-1b3d-0410-9834-0bbf25fbcc57

core/src/com/google/zxing/pdf417/PDF417Common.java

@@ -15,6 +15,8 @@
  */
 package com.google.zxing.pdf417;
 
+import java.util.Collection;
+
 /**
  * @author SITA Lab (kevin.osullivan@sita.aero)
  * @author Guenther Grau
@@ -22,8 +24,9 @@ package com.google.zxing.pdf417;
 public final class PDF417Common {
 
   public static final int NUMBER_OF_CODEWORDS = 929;
-  // Maximum Codewords (Data + Error). Was designed to be the same as the number of codewords
+  // Maximum Codewords (Data + Error).
-  public static final int MAX_CODEWORDS_IN_BARCODE = NUMBER_OF_CODEWORDS;
+  public static final int MAX_CODEWORDS_IN_BARCODE = NUMBER_OF_CODEWORDS - 1;
+  public static final int MIN_ROWS_IN_BARCODE = 3;
   public static final int MAX_ROWS_IN_BARCODE = 90;
   // One left row indication column + max 30 data columns + one right row indicator column
   public static final int MAX_CODEWORDS_IN_ROW = 32;
@@ -31,6 +34,8 @@ public final class PDF417Common {
   public static final int MODULES_IN_STOP_PATTERN = 18;
   public static final int BARS_IN_MODULE = 8;
 
+  private static final int[] EMPTY_INT_ARRAY = {};
+
   private PDF417Common() {
   }
 
@@ -41,7 +46,19 @@ public final class PDF417Common {
     }
     return bitCountSum;
   }
-  
+
+  public static int[] toIntArray(Collection<Integer> list) {
+    if (list == null || list.isEmpty()) {
+      return EMPTY_INT_ARRAY;
+    }
+    int[] result = new int[list.size()];
+    int i = 0;
+    for (Integer integer : list) {
+      result[i++] = integer;
+    }
+    return result;
+  }
+
   /**
    * Translate the symbol into a codeword.
    *
@@ -317,7 +334,7 @@ public final class PDF417Common {
       0x1f9d4, 0x1fa1a, 0x1fa2e, 0x1fa32, 0x1fa34, 0x1fa4e, 0x1fa5c, 0x1fa62, 0x1fa64, 0x1fa68, 0x1fa76, 0x1fa8e,
       0x1fa9c, 0x1fab8, 0x1fac2, 0x1fac4, 0x1fac8, 0x1fad0, 0x1fade, 0x1fae6, 0x1faec, 0x1fb16, 0x1fb26, 0x1fb2c,
       0x1fb3a, 0x1fb46, 0x1fb4c, 0x1fb58, 0x1fb6e, 0x1fb72, 0x1fb74, 0x1fb8a, 0x1fb92, 0x1fb94, 0x1fba2, 0x1fba4,
-      0x1fba8, 0x1fbb6, 0x1fbda };
+      0x1fba8, 0x1fbb6, 0x1fbda};
 
   /**
    * This table contains to codewords for all symbols.
@@ -462,5 +479,5 @@ public final class PDF417Common {
       440, 437, 1497, 1494, 1490, 1503, 761, 709, 707, 1706, 913, 912, 2198, 1386, 2164, 2161, 1621, 1766, 2103, 1208,
       2058, 2054, 1145, 1142, 2005, 2002, 1999, 2009, 1488, 1429, 1426, 2200, 1698, 1659, 1656, 1975, 1053, 1957, 1954,
       1001, 998, 1924, 1921, 1918, 1928, 937, 934, 931, 1879, 1876, 1873, 1870, 945, 1885, 1882, 1323, 1273, 1270,
-      2105, 1202, 1199, 1196, 1211, 2061, 2057, 1576, 1543, 1540, 1484, 1481, 1478, 1491, 1700 };
+      2105, 1202, 1199, 1196, 1211, 2061, 2057, 1576, 1543, 1540, 1484, 1481, 1478, 1491, 1700};
 }

core/src/com/google/zxing/pdf417/PDF417Reader.java

@@ -84,7 +84,7 @@ public final class PDF417Reader implements Reader, MultipleBarcodeReader {
   private static Result[] decode(BinaryBitmap image, Map<DecodeHintType, ?> hints, boolean multiple) 
       throws NotFoundException, FormatException, ChecksumException {
     List<Result> results = new ArrayList<Result>();
-    PDF417DetectorResult detectorResult = new Detector(image).detect(multiple);
+    PDF417DetectorResult detectorResult = Detector.detect(image, hints, multiple);
     for (ResultPoint[] points : detectorResult.getPoints()) {
       DecoderResult decoderResult = PDF417ScanningDecoder.decode(detectorResult.getBits(), points[4], points[5],
           points[6], points[7], getMinCodewordWidth(points), getMaxCodewordWidth(points));

core/src/com/google/zxing/pdf417/decoder/BarcodeMatrix.java

@@ -1,55 +0,0 @@
-/*
- * Copyright 2013 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.pdf417.decoder;
-
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * @author Guenther Grau
- */
-final class BarcodeMatrix {
-  
-  private final Map<String,BarcodeValue> values = new HashMap<String,BarcodeValue>();
-  private int maxRow = -1;
-  private int maxColumn = -1;
-
-  private static String getKey(int barcodeRow, int barcodeColumn) {
-    return barcodeRow + "," + barcodeColumn;
-  }
-
-  void setValue(int row, int column, int value) {
-    maxRow = Math.max(maxRow, row);
-    maxColumn = Math.max(maxColumn, column);
-    String key = getKey(row, column);
-    BarcodeValue barcodeValue = values.get(key);
-    if (barcodeValue == null) {
-      barcodeValue = new BarcodeValue();
-      values.put(key, barcodeValue);
-    }
-    barcodeValue.setValue(value);
-  }
-
-  public Integer getValue(int row, int column) {
-    BarcodeValue barcodeValue = values.get(getKey(row, column));
-    if (barcodeValue == null) {
-      return null;
-    }
-    return barcodeValue.getValue();
-  }
-
-}

core/src/com/google/zxing/pdf417/decoder/BarcodeValue.java

@@ -16,6 +16,10 @@
 
 package com.google.zxing.pdf417.decoder;
 
+import com.google.zxing.pdf417.PDF417Common;
+
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -24,10 +28,13 @@ import java.util.Map.Entry;
  * @author Guenther Grau
  */
 final class BarcodeValue {
-  
   private final Map<Integer,Integer> values = new HashMap<Integer,Integer>();
 
-  public void setValue(int value) {
+  /**
+   * Add an occurrence of a value
+   * @param value
+   */
+  void setValue(int value) {
     Integer confidence = values.get(value);
     if (confidence == null) {
       confidence = 0;
@@ -36,24 +43,23 @@ final class BarcodeValue {
     values.put(value, confidence);
   }
 
-  public Integer getValue() {
+  /**
+   * Determines the maximum occurrence of a set value and returns all values which were set with this occurrence. 
+   * @return an array of int, containing the values with the highest occurrence, or null, if no value was set
+   */
+  int[] getValue() {
     int maxConfidence = -1;
-    Integer result = null;
+    Collection<Integer> result = new ArrayList<Integer>();
-    boolean ambiguous = false;
     for (Entry<Integer,Integer> entry : values.entrySet()) {
       if (entry.getValue() > maxConfidence) {
         maxConfidence = entry.getValue();
-        result = entry.getKey();
+        result.clear();
-        ambiguous = false;
+        result.add(entry.getKey());
-      // TODO fix this clause?
+      } else if (entry.getValue() == maxConfidence) {
-      //} else if (entry.getValue() > maxConfidence) {
+        result.add(entry.getKey());
-      //  ambigous = true;
       }
     }
-    if (ambiguous) {
+    return PDF417Common.toIntArray(result);
-      return null;
-    }
-    return result;
   }
 
   public Integer getConfidence(int value) {

core/src/com/google/zxing/pdf417/decoder/BoundingBox.java

@@ -24,7 +24,7 @@ import com.google.zxing.common.BitMatrix;
  * @author Guenther Grau
  */
 final class BoundingBox {
-  
+
   private BitMatrix image;
   private ResultPoint topLeft;
   private ResultPoint bottomLeft;
@@ -40,8 +40,10 @@ final class BoundingBox {
               ResultPoint bottomLeft,
               ResultPoint topRight,
               ResultPoint bottomRight) throws NotFoundException {
-    if ((topLeft == null && topRight == null) || (bottomLeft == null && bottomRight == null) ||
+    if ((topLeft == null && topRight == null) ||
-        (topLeft != null && bottomLeft == null) || (topRight != null && bottomRight == null)) {
+        (bottomLeft == null && bottomRight == null) ||
+        (topLeft != null && bottomLeft == null) ||
+        (topRight != null && bottomRight == null)) {
       throw NotFoundException.getNotFoundInstance();
     }
     init(image, topLeft, bottomLeft, topRight, bottomRight);
@@ -51,11 +53,10 @@ final class BoundingBox {
     init(boundingBox.image, boundingBox.topLeft, boundingBox.bottomLeft, boundingBox.topRight, boundingBox.bottomRight);
   }
 
-  private void init(BitMatrix image, 
+  private void init(BitMatrix image,
-                    ResultPoint topLeft, 
+                    ResultPoint topLeft,
                     ResultPoint bottomLeft,
-                    
+                    ResultPoint topRight,
-                     ResultPoint topRight, 
                     ResultPoint bottomRight) {
     this.image = image;
     this.topLeft = topLeft;
@@ -75,7 +76,12 @@ final class BoundingBox {
     return new BoundingBox(leftBox.image, leftBox.topLeft, leftBox.bottomLeft, rightBox.topRight, rightBox.bottomRight);
   }
 
-  void addMissingRows(int missingStartRows, int missingEndRows, boolean isLeft) {
+  BoundingBox addMissingRows(int missingStartRows, int missingEndRows, boolean isLeft) throws NotFoundException {
+    ResultPoint newTopLeft = topLeft;
+    ResultPoint newBottomLeft = bottomLeft;
+    ResultPoint newTopRight = topRight;
+    ResultPoint newBottomRight = bottomRight;
+
     if (missingStartRows > 0) {
       ResultPoint top = isLeft ? topLeft : topRight;
       int newMinY = (int) top.getY() - missingStartRows;
@@ -85,27 +91,29 @@ final class BoundingBox {
       // TODO use existing points to better interpolate the new x positions
       ResultPoint newTop = new ResultPoint(top.getX(), newMinY);
       if (isLeft) {
-        topLeft = newTop;
+        newTopLeft = newTop;
       } else {
-        topRight = newTop;
+        newTopRight = newTop;
       }
     }
 
     if (missingEndRows > 0) {
       ResultPoint bottom = isLeft ? bottomLeft : bottomRight;
-      int newMaxY = (int) bottom.getY() - missingStartRows;
+      int newMaxY = (int) bottom.getY() + missingEndRows;
       if (newMaxY >= image.getHeight()) {
         newMaxY = image.getHeight() - 1;
       }
       // TODO use existing points to better interpolate the new x positions
       ResultPoint newBottom = new ResultPoint(bottom.getX(), newMaxY);
       if (isLeft) {
-        bottomLeft = newBottom;
+        newBottomLeft = newBottom;
       } else {
-        bottomRight = newBottom;
+        newBottomRight = newBottom;
       }
     }
+
     calculateMinMaxValues();
+    return new BoundingBox(image, newTopLeft, newBottomLeft, newTopRight, newBottomRight);
   }
 
   private void calculateMinMaxValues() {

core/src/com/google/zxing/pdf417/decoder/Codeword.java

@@ -76,4 +76,9 @@ final class Codeword {
     this.rowNumber = rowNumber;
   }
 
+  @Override
+  public String toString() {
+    return rowNumber + "|" + value;
+  }
+
 }

core/src/com/google/zxing/pdf417/decoder/DetectionResult.java

@@ -16,16 +16,20 @@
 
 package com.google.zxing.pdf417.decoder;
 
+import com.google.zxing.pdf417.PDF417Common;
+
+import java.util.Formatter;
+
 /**
  * @author Guenther Grau
  */
 final class DetectionResult {
-  
+
   private static final int ADJUST_ROW_NUMBER_SKIP = 2;
-  
+
   private final BarcodeMetadata barcodeMetadata;
   private final DetectionResultColumn[] detectionResultColumns;
-  private final BoundingBox boundingBox;
+  private BoundingBox boundingBox;
   private final int barcodeColumnCount;
 
   DetectionResult(BarcodeMetadata barcodeMetadata, BoundingBox boundingBox) {
@@ -35,44 +39,10 @@ final class DetectionResult {
     detectionResultColumns = new DetectionResultColumn[barcodeColumnCount + 2];
   }
 
-  int getImageStartRow(int barcodeColumn) {
-    while (barcodeColumn > 0) {
-      DetectionResultColumn detectionResultColumn = detectionResultColumns[--barcodeColumn];
-      // TODO compare start row with previous result columns
-      // Could try detecting codewords from right to left
-      // if all else fails, could calculate estimate
-      Codeword[] codewords = detectionResultColumn.getCodewords();
-      for (int rowNumber = 0; rowNumber < codewords.length; rowNumber++) {
-        if (codewords[rowNumber] != null) {
-          // next column might start earlier if barcode is not aligned with image
-          if (rowNumber > 0) {
-            rowNumber--;
-          }
-          return detectionResultColumn.getImageRow(rowNumber);
-        }
-      }
-    }
-    return -1;
-  }
-
-  void setDetectionResultColumn(int barcodeColumn, DetectionResultColumn detectionResultColumn) {
-    detectionResultColumns[barcodeColumn] = detectionResultColumn;
-  }
-
-  DetectionResultColumn getDetectionResultColumn(int barcodeColumn) {
-    return detectionResultColumns[barcodeColumn];
-  }
-
-  private void adjustIndicatorColumnRowNumbers(DetectionResultColumn detectionResultColumn) {
-    if (detectionResultColumn != null) {
-      ((DetectionResultRowIndicatorColumn) detectionResultColumn).adjustIndicatorColumnRowNumbers(barcodeMetadata);
-    }
-  }
-
   DetectionResultColumn[] getDetectionResultColumns() {
     adjustIndicatorColumnRowNumbers(detectionResultColumns[0]);
     adjustIndicatorColumnRowNumbers(detectionResultColumns[barcodeColumnCount + 1]);
-    int unadjustedCodewordCount = 900;
+    int unadjustedCodewordCount = PDF417Common.MAX_CODEWORDS_IN_BARCODE;
     int previousUnadjustedCount;
     do {
       previousUnadjustedCount = unadjustedCodewordCount;
@@ -81,6 +51,13 @@ final class DetectionResult {
     return detectionResultColumns;
   }
 
+  private void adjustIndicatorColumnRowNumbers(DetectionResultColumn detectionResultColumn) {
+    if (detectionResultColumn != null) {
+      ((DetectionResultRowIndicatorColumn) detectionResultColumn)
+          .adjustCompleteIndicatorColumnRowNumbers(barcodeMetadata);
+    }
+  }
+
   // TODO ensure that no detected codewords with unknown row number are left
   // we should be able to estimate the row height and use it as a hint for the row number
   // we should also fill the rows top to bottom and bottom to top
@@ -108,6 +85,7 @@ final class DetectionResult {
   }
 
   private int adjustRowNumbersByRow() {
+    adjustRowNumbersFromBothRI();
     // TODO we should only do full row adjustments if row numbers of left and right row indicator column match.
     // Maybe it's even better to calculated the height (in codeword rows) and divide it by the number of barcode
     // rows. This, together with the LRI and RRI row numbers should allow us to get a good estimate where a row
@@ -116,6 +94,31 @@ final class DetectionResult {
     return unadjustedCount + adjustRowNumbersFromRRI();
   }
 
+  private int adjustRowNumbersFromBothRI() {
+    if (detectionResultColumns[0] == null || detectionResultColumns[barcodeColumnCount + 1] == null) {
+      return 0;
+    }
+    Codeword[] LRIcodewords = detectionResultColumns[0].getCodewords();
+    Codeword[] RRIcodewords = detectionResultColumns[barcodeColumnCount + 1].getCodewords();
+    for (int codewordsRow = 0; codewordsRow < LRIcodewords.length; codewordsRow++) {
+      if (LRIcodewords[codewordsRow] != null &&
+          RRIcodewords[codewordsRow] != null &&
+          LRIcodewords[codewordsRow].getRowNumber() == RRIcodewords[codewordsRow].getRowNumber()) {
+        for (int barcodeColumn = 1; barcodeColumn <= barcodeColumnCount; barcodeColumn++) {
+          Codeword codeword = detectionResultColumns[barcodeColumn].getCodewords()[codewordsRow];
+          if (codeword == null) {
+            continue;
+          }
+          codeword.setRowNumber(LRIcodewords[codewordsRow].getRowNumber());
+          if (!codeword.hasValidRowNumber()) {
+            detectionResultColumns[barcodeColumn].getCodewords()[codewordsRow] = null;
+          }
+        }
+      }
+    }
+    return 0;
+  }
+
   private int adjustRowNumbersFromRRI() {
     if (detectionResultColumns[barcodeColumnCount + 1] == null) {
       return 0;
@@ -128,9 +131,7 @@ final class DetectionResult {
       }
       int rowIndicatorRowNumber = codewords[codewordsRow].getRowNumber();
       int invalidRowCounts = 0;
-      for (int barcodeColumn = barcodeColumnCount + 1; 
+      for (int barcodeColumn = barcodeColumnCount + 1; barcodeColumn > 0 && invalidRowCounts < ADJUST_ROW_NUMBER_SKIP; barcodeColumn--) {
-           barcodeColumn > 0 && invalidRowCounts < ADJUST_ROW_NUMBER_SKIP; 
-           barcodeColumn--) {
         Codeword codeword = detectionResultColumns[barcodeColumn].getCodewords()[codewordsRow];
         if (codeword != null) {
           invalidRowCounts = adjustRowNumberIfValid(rowIndicatorRowNumber, invalidRowCounts, codeword);
@@ -155,9 +156,7 @@ final class DetectionResult {
       }
       int rowIndicatorRowNumber = codewords[codewordsRow].getRowNumber();
       int invalidRowCounts = 0;
-      for (int barcodeColumn = 1; 
+      for (int barcodeColumn = 1; barcodeColumn < barcodeColumnCount + 1 && invalidRowCounts < ADJUST_ROW_NUMBER_SKIP; barcodeColumn++) {
-           barcodeColumn < barcodeColumnCount + 1 && invalidRowCounts < ADJUST_ROW_NUMBER_SKIP; 
-           barcodeColumn++) {
         Codeword codeword = detectionResultColumns[barcodeColumn].getCodewords()[codewordsRow];
         if (codeword != null) {
           invalidRowCounts = adjustRowNumberIfValid(rowIndicatorRowNumber, invalidRowCounts, codeword);
@@ -171,7 +170,6 @@ final class DetectionResult {
   }
 
   private static int adjustRowNumberIfValid(int rowIndicatorRowNumber, int invalidRowCounts, Codeword codeword) {
-
     if (codeword == null) {
       return invalidRowCounts;
     }
@@ -252,8 +250,48 @@ final class DetectionResult {
     return barcodeMetadata.getErrorCorrectionLevel();
   }
 
+  public void setBoundingBox(BoundingBox boundingBox) {
+    this.boundingBox = boundingBox;
+  }
+
   BoundingBox getBoundingBox() {
     return boundingBox;
   }
 
+  void setDetectionResultColumn(int barcodeColumn, DetectionResultColumn detectionResultColumn) {
+    detectionResultColumns[barcodeColumn] = detectionResultColumn;
+  }
+
+  DetectionResultColumn getDetectionResultColumn(int barcodeColumn) {
+    return detectionResultColumns[barcodeColumn];
+  }
+
+  @Override
+  public String toString() {
+    DetectionResultColumn rowIndicatorColumn = detectionResultColumns[0];
+    if (rowIndicatorColumn == null) {
+      rowIndicatorColumn = detectionResultColumns[barcodeColumnCount + 1];
+    }
+    Formatter formatter = new Formatter();
+    for (int codewordsRow = 0; codewordsRow < rowIndicatorColumn.getCodewords().length; codewordsRow++) {
+      formatter.format("CW %3d:", codewordsRow);
+      for (int barcodeColumn = 0; barcodeColumn < barcodeColumnCount + 2; barcodeColumn++) {
+        if (detectionResultColumns[barcodeColumn] == null) {
+          formatter.format("    |   ");
+          continue;
+        }
+        Codeword codeword = detectionResultColumns[barcodeColumn].getCodewords()[codewordsRow];
+        if (codeword == null) {
+          formatter.format("    |   ");
+          continue;
+        }
+        formatter.format(" %3d|%3d", codeword.getRowNumber(), codeword.getValue());
+      }
+      formatter.format("\n");
+    }
+    String result = formatter.toString();
+    formatter.close();
+    return result;
+  }
+
 }

core/src/com/google/zxing/pdf417/decoder/DetectionResultColumn.java

@@ -16,6 +16,8 @@
 
 package com.google.zxing.pdf417.decoder;
 
+import java.util.Formatter;
+
 /**
  * @author Guenther Grau
  */
@@ -37,14 +39,14 @@ class DetectionResultColumn {
       return codeword;
     }
     for (int i = 1; i < MAX_NEARBY_DISTANCE; i++) {
-      int nearImageRow = getCodewordsIndex(imageRow) - i;
+      int nearImageRow = imageRowToCodewordIndex(imageRow) - i;
       if (nearImageRow >= 0) {
         codeword = codewords[nearImageRow];
         if (codeword != null) {
           return codeword;
         }
       }
-      nearImageRow = getCodewordsIndex(imageRow) + i;
+      nearImageRow = imageRowToCodewordIndex(imageRow) + i;
       if (nearImageRow < codewords.length) {
         codeword = codewords[nearImageRow];
         if (codeword != null) {
@@ -55,20 +57,20 @@ class DetectionResultColumn {
     return null;
   }
 
-  final int getCodewordsIndex(int imageRow) {
+  final int imageRowToCodewordIndex(int imageRow) {
     return imageRow - boundingBox.getMinY();
   }
 
-  final int getImageRow(int codewordIndex) {
+  final int codewordIndexToImageRow(int codewordIndex) {
     return boundingBox.getMinY() + codewordIndex;
   }
 
   final void setCodeword(int imageRow, Codeword codeword) {
-    codewords[getCodewordsIndex(imageRow)] = codeword;
+    codewords[imageRowToCodewordIndex(imageRow)] = codeword;
   }
 
   final Codeword getCodeword(int imageRow) {
-    return codewords[getCodewordsIndex(imageRow)];
+    return codewords[imageRowToCodewordIndex(imageRow)];
   }
 
   final BoundingBox getBoundingBox() {
@@ -79,4 +81,20 @@ class DetectionResultColumn {
     return codewords;
   }
 
+  @Override
+  public String toString() {
+    Formatter formatter = new Formatter();
+    int row = 0;
+    for (Codeword codeword : codewords) {
+      if (codeword == null) {
+        formatter.format("%3d:    |   \n", row++);
+        continue;
+      }
+      formatter.format("%3d: %3d|%3d\n", row++, codeword.getRowNumber(), codeword.getValue());
+    }
+    String result = formatter.toString();
+    formatter.close();
+    return result;
+  }
+
 }

core/src/com/google/zxing/pdf417/decoder/DetectionResultRowIndicatorColumn.java

@@ -17,15 +17,13 @@
 package com.google.zxing.pdf417.decoder;
 
 import com.google.zxing.ResultPoint;
+import com.google.zxing.pdf417.PDF417Common;
 
 /**
  * @author Guenther Grau
  */
 final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
 
-  private static final int MIN_BARCODE_ROWS = 3;
-  private static final int MAX_BARCODE_ROWS = 90;
-
   private final boolean isLeft;
 
   DetectionResultRowIndicatorColumn(BoundingBox boundingBox, boolean isLeft) {
@@ -41,32 +39,22 @@ final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
     }
   }
 
-  int[] getRowHeights() {
+  // TODO implement properly
-    BarcodeMetadata barcodeMetadata = getBarcodeMetadata();
-    if (barcodeMetadata == null) {
-      return null;
-    }
-    adjustIndicatorColumnRowNumbers(barcodeMetadata);
-    int[] result = new int[barcodeMetadata.getRowCount()];
-    for (Codeword codeword : getCodewords()) {
-      if (codeword != null) {
-        result[codeword.getRowNumber()]++;
-      }
-    }
-    return result;
-  }
-
   // TODO maybe we should add missing codewords to store the correct row number to make
   // finding row numbers for other columns easier
   // use row height count to make detection of invalid row numbers more reliable
-  int adjustIndicatorColumnRowNumbers(BarcodeMetadata barcodeMetadata) {
+  int adjustCompleteIndicatorColumnRowNumbers(BarcodeMetadata barcodeMetadata) {
+    Codeword[] codewords = getCodewords();
+    setRowNumbers();
+    removeIncorrectCodewords(codewords, barcodeMetadata);
     BoundingBox boundingBox = getBoundingBox();
     ResultPoint top = isLeft ? boundingBox.getTopLeft() : boundingBox.getTopRight();
     ResultPoint bottom = isLeft ? boundingBox.getBottomLeft() : boundingBox.getBottomRight();
-    int firstRow = getCodewordsIndex((int) top.getY());
+    int firstRow = imageRowToCodewordIndex((int) top.getY());
-    int lastRow = getCodewordsIndex((int) bottom.getY());
+    int lastRow = imageRowToCodewordIndex((int) bottom.getY());
+    // We need to be careful using the average row height. Barcode could be skewed so that we have smaller and 
+    // taller rows
     float averageRowHeight = (lastRow - firstRow) / (float) barcodeMetadata.getRowCount();
-    Codeword[] codewords = getCodewords();
     int barcodeRow = -1;
     int maxRowHeight = 1;
     int currentRowHeight = 0;
@@ -76,11 +64,6 @@ final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
       }
       Codeword codeword = codewords[codewordsRow];
 
-      codeword.setRowNumberAsRowIndicatorColumn();
-
-      // This only works if we have a complete RI column. If the RI column is cut off at the top or bottom, it
-      // will calculate the wrong numbers and delete correct codewords. Could be used once the barcode height has
-      // been calculated properly.
       //      float expectedRowNumber = (codewordsRow - firstRow) / averageRowHeight;
       //      if (Math.abs(codeword.getRowNumber() - expectedRowNumber) > 2) {
       //        SimpleLog.log(LEVEL.WARNING,
@@ -129,6 +112,63 @@ final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
     return (int) (averageRowHeight + 0.5);
   }
 
+  int[] getRowHeights() {
+    BarcodeMetadata barcodeMetadata = getBarcodeMetadata();
+    if (barcodeMetadata == null) {
+      return null;
+    }
+    adjustIncompleteIndicatorColumnRowNumbers(barcodeMetadata);
+    int[] result = new int[barcodeMetadata.getRowCount()];
+    for (Codeword codeword : getCodewords()) {
+      if (codeword != null) {
+        result[codeword.getRowNumber()]++;
+      }
+    }
+    return result;
+  }
+
+  // TODO maybe we should add missing codewords to store the correct row number to make
+  // finding row numbers for other columns easier
+  // use row height count to make detection of invalid row numbers more reliable
+  int adjustIncompleteIndicatorColumnRowNumbers(BarcodeMetadata barcodeMetadata) {
+    BoundingBox boundingBox = getBoundingBox();
+    ResultPoint top = isLeft ? boundingBox.getTopLeft() : boundingBox.getTopRight();
+    ResultPoint bottom = isLeft ? boundingBox.getBottomLeft() : boundingBox.getBottomRight();
+    int firstRow = imageRowToCodewordIndex((int) top.getY());
+    int lastRow = imageRowToCodewordIndex((int) bottom.getY());
+    float averageRowHeight = (lastRow - firstRow) / (float) barcodeMetadata.getRowCount();
+    Codeword[] codewords = getCodewords();
+    int barcodeRow = -1;
+    int maxRowHeight = 1;
+    int currentRowHeight = 0;
+    for (int codewordsRow = firstRow; codewordsRow < lastRow; codewordsRow++) {
+      if (codewords[codewordsRow] == null) {
+        continue;
+      }
+      Codeword codeword = codewords[codewordsRow];
+
+      codeword.setRowNumberAsRowIndicatorColumn();
+
+      int rowDifference = codeword.getRowNumber() - barcodeRow;
+
+      // TODO improve handling with case where first row indicator doesn't start with 0
+
+      if (rowDifference == 0) {
+        currentRowHeight++;
+      } else if (rowDifference == 1) {
+        maxRowHeight = Math.max(maxRowHeight, currentRowHeight);
+        currentRowHeight = 1;
+        barcodeRow = codeword.getRowNumber();
+      } else if (codeword.getRowNumber() >= barcodeMetadata.getRowCount()) {
+        codewords[codewordsRow] = null;
+      } else {
+        barcodeRow = codeword.getRowNumber();
+        currentRowHeight = 1;
+      }
+    }
+    return (int) (averageRowHeight + 0.5);
+  }
+
   BarcodeMetadata getBarcodeMetadata() {
     Codeword[] codewords = getCodewords();
     BarcodeValue barcodeColumnCount = new BarcodeValue();
@@ -158,15 +198,18 @@ final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
           break;
       }
     }
-    if ((barcodeColumnCount.getValue() == null) || (barcodeRowCountUpperPart.getValue() == null) ||
+    // Maybe we should check if we have ambiguous values?
-        (barcodeRowCountLowerPart.getValue() == null) || (barcodeECLevel.getValue() == null) ||
+    if ((barcodeColumnCount.getValue().length == 0) ||
-        barcodeColumnCount.getValue() < 1 ||
+        (barcodeRowCountUpperPart.getValue().length == 0) ||
-        barcodeRowCountUpperPart.getValue() + barcodeRowCountLowerPart.getValue() < MIN_BARCODE_ROWS ||
+        (barcodeRowCountLowerPart.getValue().length == 0) ||
-        barcodeRowCountUpperPart.getValue() + barcodeRowCountLowerPart.getValue() > MAX_BARCODE_ROWS) {
+        (barcodeECLevel.getValue().length == 0) ||
+        barcodeColumnCount.getValue()[0] < 1 ||
+        barcodeRowCountUpperPart.getValue()[0] + barcodeRowCountLowerPart.getValue()[0] < PDF417Common.MIN_ROWS_IN_BARCODE ||
+        barcodeRowCountUpperPart.getValue()[0] + barcodeRowCountLowerPart.getValue()[0] > PDF417Common.MAX_ROWS_IN_BARCODE) {
       return null;
     }
-    BarcodeMetadata barcodeMetadata = new BarcodeMetadata(barcodeColumnCount.getValue(),
+    BarcodeMetadata barcodeMetadata = new BarcodeMetadata(barcodeColumnCount.getValue()[0],
-        barcodeRowCountUpperPart.getValue(), barcodeRowCountLowerPart.getValue(), barcodeECLevel.getValue());
+        barcodeRowCountUpperPart.getValue()[0], barcodeRowCountLowerPart.getValue()[0], barcodeECLevel.getValue()[0]);
     removeIncorrectCodewords(codewords, barcodeMetadata);
     return barcodeMetadata;
   }
@@ -213,4 +256,9 @@ final class DetectionResultRowIndicatorColumn extends DetectionResultColumn {
     return isLeft;
   }
 
+  @Override
+  public String toString() {
+    return "IsLeft: " + isLeft + '\n' + super.toString();
+  }
+
 }

core/src/com/google/zxing/pdf417/decoder/PDF417ScanningDecoder.java

@@ -27,14 +27,14 @@ import com.google.zxing.pdf417.decoder.ec.ErrorCorrection;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Formatter;
+import java.util.List;
 
 /**
  * @author Guenther Grau
  */
 public final class PDF417ScanningDecoder {
 
-  private static final int ROW_HEIGHT_SKEW = 2;
-  //  private static final int STOP_PATTERN_VALUE = 130324;
   private static final int CODEWORD_SKEW_SIZE = 2;
 
   private static final int MAX_ERRORS = 3;
@@ -44,44 +44,41 @@ public final class PDF417ScanningDecoder {
   private PDF417ScanningDecoder() {
   }
 
-
   // TODO don't pass in minCodewordWidth and maxCodewordWidth, pass in barcode columns for start and stop pattern
   // columns. That way width can be deducted from the pattern column.
   // This approach also allows to detect more details about the barcode, e.g. if a bar type (white or black) is wider 
   // than it should be. This can happen if the scanner used a bad blackpoint.
-  public static DecoderResult decode(BitMatrix image, 
+  public static DecoderResult decode(BitMatrix image,
                                      ResultPoint imageTopLeft,
-                                     ResultPoint imageBottomLeft, 
+                                     ResultPoint imageBottomLeft,
                                      ResultPoint imageTopRight,
                                      ResultPoint imageBottomRight,
                                      int minCodewordWidth,
-                                     int maxCodewordWidth) 
+                                     int maxCodewordWidth) throws NotFoundException, FormatException, ChecksumException {
-      throws NotFoundException, FormatException, ChecksumException {
     BoundingBox boundingBox = new BoundingBox(image, imageTopLeft, imageBottomLeft, imageTopRight, imageBottomRight);
     DetectionResultRowIndicatorColumn leftRowIndicatorColumn = null;
     DetectionResultRowIndicatorColumn rightRowIndicatorColumn = null;
     DetectionResult detectionResult = null;
-    boolean again = true;
+    for (int i = 0; i < 2; i++) {
-    while (again) {
-      again = false;
       if (imageTopLeft != null) {
         leftRowIndicatorColumn = getRowIndicatorColumn(image, boundingBox, imageTopLeft, true, minCodewordWidth,
             maxCodewordWidth);
-        leftRowIndicatorColumn.setRowNumbers();
       }
       if (imageTopRight != null) {
         rightRowIndicatorColumn = getRowIndicatorColumn(image, boundingBox, imageTopRight, false, minCodewordWidth,
             maxCodewordWidth);
-        rightRowIndicatorColumn.setRowNumbers();
       }
       detectionResult = merge(leftRowIndicatorColumn, rightRowIndicatorColumn);
       if (detectionResult == null) {
         throw NotFoundException.getNotFoundInstance();
       }
-      if (detectionResult.getBoundingBox().getMinY() < boundingBox.getMinY() ||
+      if (i == 0 &&
-          detectionResult.getBoundingBox().getMaxY() > boundingBox.getMaxY()) {
+          (detectionResult.getBoundingBox().getMinY() < boundingBox.getMinY() || detectionResult.getBoundingBox()
+              .getMaxY() > boundingBox.getMaxY())) {
         boundingBox = detectionResult.getBoundingBox();
-        again = true;
+      } else {
+        detectionResult.setBoundingBox(boundingBox);
+        break;
       }
     }
     int maxBarcodeColumn = detectionResult.getBarcodeColumnCount() + 1;
@@ -105,7 +102,7 @@ public final class PDF417ScanningDecoder {
       int startColumn = -1;
       int previousStartColumn = startColumn;
       // TODO start at a row for which we know the start position, then detect upwards and downwards from there.
-      for (int imageRow = boundingBox.getMinY(); imageRow < boundingBox.getMaxY(); imageRow++) {
+      for (int imageRow = boundingBox.getMinY(); imageRow <= boundingBox.getMaxY(); imageRow++) {
         startColumn = getStartColumn(detectionResult, barcodeColumn, imageRow, leftToRight);
         if (startColumn < 0 || startColumn > boundingBox.getMaxX()) {
           if (previousStartColumn == -1) {
@@ -136,20 +133,13 @@ public final class PDF417ScanningDecoder {
     if (barcodeMetadata == null) {
       return null;
     }
-    BoundingBox boundingBox = getBoundingBox(leftRowIndicatorColumn, rightRowIndicatorColumn);
+    BoundingBox boundingBox = BoundingBox.merge(adjustBoundingBox(leftRowIndicatorColumn),
+        adjustBoundingBox(rightRowIndicatorColumn));
     return new DetectionResult(barcodeMetadata, boundingBox);
   }
 
-  private static BoundingBox getBoundingBox(DetectionResultRowIndicatorColumn leftRowIndicatorColumn,
+  private static BoundingBox adjustBoundingBox(DetectionResultRowIndicatorColumn rowIndicatorColumn)
-                                            DetectionResultRowIndicatorColumn rightRowIndicatorColumn)
       throws NotFoundException {
-    BoundingBox box1 = adjustBoundingBox(leftRowIndicatorColumn);
-    BoundingBox box2 = adjustBoundingBox(rightRowIndicatorColumn);
-
-    return BoundingBox.merge(box1, box2);
-  }
-
-  private static BoundingBox adjustBoundingBox(DetectionResultRowIndicatorColumn rowIndicatorColumn) {
     if (rowIndicatorColumn == null) {
       return null;
     }
@@ -157,23 +147,27 @@ public final class PDF417ScanningDecoder {
     int maxRowHeight = getMax(rowHeights);
     int missingStartRows = 0;
     for (int rowHeight : rowHeights) {
-      if (rowHeight < maxRowHeight - ROW_HEIGHT_SKEW) {
+      missingStartRows += maxRowHeight - rowHeight;
-        missingStartRows++;
+      if (rowHeight > 0) {
-      } else {
         break;
       }
     }
+    Codeword[] codewords = rowIndicatorColumn.getCodewords();
+    for (int row = 0; missingStartRows > 0 && codewords[row] == null; row++) {
+      missingStartRows--;
+    }
     int missingEndRows = 0;
     for (int row = rowHeights.length - 1; row >= 0; row--) {
-      if (rowHeights[row] < maxRowHeight - ROW_HEIGHT_SKEW) {
+      missingEndRows += maxRowHeight - rowHeights[row];
-        missingEndRows++;
+      if (rowHeights[row] > 0) {
-      } else {
         break;
       }
     }
-    rowIndicatorColumn.getBoundingBox().addMissingRows(missingStartRows * maxRowHeight, missingEndRows * maxRowHeight,
+    for (int row = codewords.length - 1; missingEndRows > 0 && codewords[row] == null; row--) {
+      missingEndRows--;
+    }
+    return rowIndicatorColumn.getBoundingBox().addMissingRows(missingStartRows, missingEndRows,
         rowIndicatorColumn.isLeft());
-    return rowIndicatorColumn.getBoundingBox();
   }
 
   private static int getMax(int[] values) {
@@ -203,9 +197,12 @@ public final class PDF417ScanningDecoder {
     return leftBarcodeMetadata;
   }
 
-  private static DetectionResultRowIndicatorColumn getRowIndicatorColumn(BitMatrix image, BoundingBox boundingBox,
+  private static DetectionResultRowIndicatorColumn getRowIndicatorColumn(BitMatrix image,
-                                                                         ResultPoint startPoint, boolean leftToRight,
+                                                                         BoundingBox boundingBox,
-                                                                         int minCodewordWidth, int maxCodewordWidth) {
+                                                                         ResultPoint startPoint,
+                                                                         boolean leftToRight,
+                                                                         int minCodewordWidth,
+                                                                         int maxCodewordWidth) {
     DetectionResultRowIndicatorColumn rowIndicatorColumn = new DetectionResultRowIndicatorColumn(boundingBox,
         leftToRight);
     for (int i = 0; i < 2; i++) {
@@ -228,38 +225,114 @@ public final class PDF417ScanningDecoder {
     return rowIndicatorColumn;
   }
 
-  private static DecoderResult createDecoderResult(DetectionResult detectionResult) throws NotFoundException,
+  private static void adjustCodewordCount(DetectionResult detectionResult, BarcodeValue[][] barcodeMatrix)
-      FormatException, ChecksumException {
+      throws NotFoundException {
-    BarcodeMatrix barcodeMatrix = createBarcodeMatrix(detectionResult);
+    int[] numberOfCodewords = barcodeMatrix[0][1].getValue();
-    Integer numberOfCodewords = barcodeMatrix.getValue(0, 1);
+    int calculatedNumberOfCodewords = detectionResult.getBarcodeColumnCount() *
-    int calculatedNumberOfCodewords = detectionResult.getBarcodeColumnCount() * detectionResult.getBarcodeRowCount() -
+        detectionResult.getBarcodeRowCount() -
         getNumberOfECCodeWords(detectionResult.getBarcodeECLevel());
-    if (numberOfCodewords == null) {
+    if (numberOfCodewords.length == 0) {
       if (calculatedNumberOfCodewords < 1 || calculatedNumberOfCodewords > PDF417Common.MAX_CODEWORDS_IN_BARCODE) {
         throw NotFoundException.getNotFoundInstance();
       }
-      barcodeMatrix.setValue(0, 1, calculatedNumberOfCodewords);
+      barcodeMatrix[0][1].setValue(calculatedNumberOfCodewords);
-    } else if (numberOfCodewords != calculatedNumberOfCodewords) {
+    } else if (numberOfCodewords[0] != calculatedNumberOfCodewords) {
-      // The calculated one is more reliable as it is derived from the row indicator column
+      // The calculated one is more reliable as it is derived from the row indicator columns
-      numberOfCodewords = calculatedNumberOfCodewords;
+      barcodeMatrix[0][1].setValue(calculatedNumberOfCodewords);
     }
+  }
+
+  private static DecoderResult createDecoderResult(DetectionResult detectionResult) throws FormatException,
+      ChecksumException, NotFoundException {
+    BarcodeValue[][] barcodeMatrix = createBarcodeMatrix(detectionResult);
+    adjustCodewordCount(detectionResult, barcodeMatrix);
     Collection<Integer> erasures = new ArrayList<Integer>();
     int[] codewords = new int[detectionResult.getBarcodeRowCount() * detectionResult.getBarcodeColumnCount()];
+    List<int[]> ambiguousIndexValuesList = new ArrayList<int[]>();
+    List<Integer> ambiguousIndexesList = new ArrayList<Integer>();
     for (int row = 0; row < detectionResult.getBarcodeRowCount(); row++) {
       for (int column = 0; column < detectionResult.getBarcodeColumnCount(); column++) {
-        Integer codeword = barcodeMatrix.getValue(row, column + 1);
+        int[] values = barcodeMatrix[row][column + 1].getValue();
-        if (codeword == null) {
+        int codewordIndex = row * detectionResult.getBarcodeColumnCount() + column;
-          erasures.add(row * detectionResult.getBarcodeColumnCount() + column);
+        if (values.length == 0) {
+          erasures.add(codewordIndex);
+        } else if (values.length == 1) {
+          codewords[codewordIndex] = values[0];
         } else {
-          codewords[row * detectionResult.getBarcodeColumnCount() + column] = codeword;
+          ambiguousIndexesList.add(codewordIndex);
+          ambiguousIndexValuesList.add(values);
         }
       }
     }
-    return decodeCodewords(codewords, detectionResult.getBarcodeECLevel(), getErasureArray(erasures));
+    int[][] ambiguousIndexValues = new int[ambiguousIndexValuesList.size()][];
+    for (int i = 0; i < ambiguousIndexValues.length; i++) {
+      ambiguousIndexValues[i] = ambiguousIndexValuesList.get(i);
+    }
+    return createDecoderResultFromAmbiguousValues(detectionResult.getBarcodeECLevel(), codewords,
+        PDF417Common.toIntArray(erasures), PDF417Common.toIntArray(ambiguousIndexesList), ambiguousIndexValues);
   }
 
-  private static BarcodeMatrix createBarcodeMatrix(DetectionResult detectionResult) {
+  /**
-    BarcodeMatrix barcodeMatrix = new BarcodeMatrix();
+   * 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. 
+   * @param ecLevel
+   * @param codewords
+   * @param erasureArray contains the indexes of erasures
+   * @param ambiguousIndexes array with the indexes that have more than one most likely value
+   * @param ambiguousIndexValues two dimensional array that contains the ambiguous values. The first dimension must
+   * be the same length as the ambiguousIndexes array
+   * @return
+   * @throws FormatException
+   * @throws ChecksumException
+   */
+  private static DecoderResult createDecoderResultFromAmbiguousValues(int ecLevel,
+                                                                      int[] codewords,
+                                                                      int[] erasureArray,
+                                                                      int[] ambiguousIndexes,
+                                                                      int[][] ambiguousIndexValues)
+      throws FormatException, ChecksumException {
+    int[] ambiguousIndexCount = new int[ambiguousIndexes.length];
+
+    int tries = 100;
+    while (tries-- > 0) {
+      for (int i = 0; i < ambiguousIndexCount.length; i++) {
+        codewords[ambiguousIndexes[i]] = ambiguousIndexValues[i][ambiguousIndexCount[i]];
+      }
+      try {
+        return decodeCodewords(codewords, ecLevel, erasureArray);
+      } catch (ChecksumException ignored) {
+        //
+      }
+      if (ambiguousIndexCount.length == 0) {
+        throw ChecksumException.getChecksumInstance();
+      }
+      for (int i = 0; i < ambiguousIndexCount.length; i++) {
+        if (ambiguousIndexCount[i] < ambiguousIndexValues[i].length - 1) {
+          ambiguousIndexCount[i]++;
+          break;
+        } else {
+          ambiguousIndexCount[i] = 0;
+          if (i == ambiguousIndexCount.length - 1) {
+            throw ChecksumException.getChecksumInstance();
+          }
+        }
+      }
+    }
+    throw ChecksumException.getChecksumInstance();
+  }
+
+  private static BarcodeValue[][] createBarcodeMatrix(DetectionResult detectionResult) {
+    BarcodeValue[][] barcodeMatrix = new BarcodeValue[detectionResult.getBarcodeRowCount()][detectionResult
+        .getBarcodeColumnCount() + 2];
+    for (int row = 0; row < barcodeMatrix.length; row++) {
+      for (int column = 0; column < barcodeMatrix[row].length; column++) {
+        barcodeMatrix[row][column] = new BarcodeValue();
+      }
+    }
 
     int column = -1;
     for (DetectionResultColumn detectionResultColumn : detectionResult.getDetectionResultColumns()) {
@@ -268,10 +341,10 @@ public final class PDF417ScanningDecoder {
         continue;
       }
       for (Codeword codeword : detectionResultColumn.getCodewords()) {
-        if (codeword == null) {
+        if (codeword == null || codeword.getRowNumber() == -1) {
           continue;
         }
-        barcodeMatrix.setValue(codeword.getRowNumber(), column, codeword.getValue());
+        barcodeMatrix[codeword.getRowNumber()][column].setValue(codeword.getValue());
       }
     }
     return barcodeMatrix;
@@ -281,7 +354,9 @@ public final class PDF417ScanningDecoder {
     return barcodeColumn >= 0 && barcodeColumn <= detectionResult.getBarcodeColumnCount() + 1;
   }
 
-  private static int getStartColumn(DetectionResult detectionResult, int barcodeColumn, int imageRow,
+  private static int getStartColumn(DetectionResult detectionResult,
+                                    int barcodeColumn,
+                                    int imageRow,
                                     boolean leftToRight) {
     int offset = leftToRight ? 1 : -1;
     Codeword codeword = null;
@@ -307,8 +382,10 @@ public final class PDF417ScanningDecoder {
       barcodeColumn -= offset;
       for (Codeword previousRowCodeword : detectionResult.getDetectionResultColumn(barcodeColumn).getCodewords()) {
         if (previousRowCodeword != null) {
-          return (leftToRight ? previousRowCodeword.getEndX() : previousRowCodeword.getStartX()) + offset *
+          return (leftToRight ? previousRowCodeword.getEndX() : previousRowCodeword.getStartX()) +
-              skippedColumns * (previousRowCodeword.getEndX() - previousRowCodeword.getStartX());
+              offset *
+              skippedColumns *
+              (previousRowCodeword.getEndX() - previousRowCodeword.getStartX());
         }
       }
       skippedColumns++;
@@ -316,8 +393,14 @@ public final class PDF417ScanningDecoder {
     return leftToRight ? detectionResult.getBoundingBox().getMinX() : detectionResult.getBoundingBox().getMaxX();
   }
 
-  private static Codeword detectCodeword(BitMatrix image, int minColumn, int maxColumn, boolean leftToRight,
+  private static Codeword detectCodeword(BitMatrix image,
-                                         int startColumn, int imageRow, int minCodewordWidth, int maxCodewordWidth) {
+                                         int minColumn,
+                                         int maxColumn,
+                                         boolean leftToRight,
+                                         int startColumn,
+                                         int imageRow,
+                                         int minCodewordWidth,
+                                         int maxCodewordWidth) {
     startColumn = adjustCodewordStartColumn(image, minColumn, maxColumn, leftToRight, startColumn, imageRow);
     // we usually know fairly exact now how long a codeword is. We should provide minimum and maximum expected length
     // and try to adjust the read pixels, e.g. remove single pixel errors or try to cut off exceeding pixels.
@@ -368,8 +451,12 @@ public final class PDF417ScanningDecoder {
     return new Codeword(startColumn, endColumn, getCodewordBucketNumber(decodedValue), codeword);
   }
 
-  private static int[] getModuleBitCount(BitMatrix image, int minColumn, int maxColumn, boolean leftToRight,
+  private static int[] getModuleBitCount(BitMatrix image,
-                                         int startColumn, int imageRow) {
+                                         int minColumn,
+                                         int maxColumn,
+                                         boolean leftToRight,
+                                         int startColumn,
+                                         int imageRow) {
     int imageColumn = startColumn;
     int[] moduleBitCount = new int[8];
     int moduleNumber = 0;
@@ -396,11 +483,11 @@ public final class PDF417ScanningDecoder {
     return 2 << barcodeECLevel;
   }
 
-  private static int adjustCodewordStartColumn(BitMatrix image, 
+  private static int adjustCodewordStartColumn(BitMatrix image,
-                                               int minColumn, 
+                                               int minColumn,
                                                int maxColumn,
-                                               boolean leftToRight, 
+                                               boolean leftToRight,
-                                               int codewordStartColumn, 
+                                               int codewordStartColumn,
                                                int imageRow) {
     int correctedStartColumn = codewordStartColumn;
     int increment = leftToRight ? -1 : 1;
@@ -424,23 +511,13 @@ public final class PDF417ScanningDecoder {
         codewordSize <= maxCodewordWidth + CODEWORD_SKEW_SIZE;
   }
 
-  private static int[] getErasureArray(Collection<Integer> list) {
+  private static DecoderResult decodeCodewords(int[] codewords, int ecLevel, int[] erasures) throws FormatException,
-    int[] result = new int[list.size()];
+      ChecksumException {
-    int i = 0;
-    for (Integer integer : list) {
-      result[i++] = integer;
-    }
-    return result;
-  }
-
-  private static DecoderResult decodeCodewords(int[] codewords, int ecLevel, int[] erasures)
-      throws FormatException, ChecksumException {
     if (codewords.length == 0) {
       throw FormatException.getFormatInstance();
     }
 
     int numECCodewords = 1 << (ecLevel + 1);
-
     int correctedErrorsCount = correctErrors(codewords, erasures, numECCodewords);
     verifyCodewordCount(codewords, numECCodewords);
 
@@ -457,16 +534,20 @@ public final class PDF417ScanningDecoder {
    *
    * @param codewords   data and error correction codewords
    * @param erasures positions of any known erasures
-   * @param numECCodewords number of error correction codewards that were available in codewords
+   * @param numECCodewords number of error correction codewords that are available in codewords
    * @throws ChecksumException if error correction fails
    */
   private static int correctErrors(int[] codewords, int[] erasures, int numECCodewords) throws ChecksumException {
-    if (erasures.length > numECCodewords / 2 + MAX_ERRORS || numECCodewords < 0 || numECCodewords > MAX_EC_CODEWORDS) {
+    if (erasures != null &&
+        erasures.length > numECCodewords / 2 + MAX_ERRORS ||
+        numECCodewords < 0 ||
+        numECCodewords > MAX_EC_CODEWORDS) {
       // Too many errors or EC Codewords is corrupted
       throw ChecksumException.getChecksumInstance();
     }
     return errorCorrection.decode(codewords, numECCodewords, erasures);
   }
+
   /**
    * Verify that all is OK with the codeword array.
    *
@@ -522,4 +603,24 @@ public final class PDF417ScanningDecoder {
     return (moduleBitCount[0] - moduleBitCount[2] + moduleBitCount[4] - moduleBitCount[6] + 9) % 9;
   }
 
+  public static String toString(BarcodeValue[][] barcodeMatrix) {
+    Formatter formatter = new Formatter();
+    for (int row = 0; row < barcodeMatrix.length; row++) {
+      formatter.format("Row %2d: ", row);
+      for (int column = 0; column < barcodeMatrix[row].length; column++) {
+        BarcodeValue barcodeValue = barcodeMatrix[row][column];
+        if (barcodeValue.getValue().length == 0) {
+          formatter.format("        ", (Object[]) null);
+        } else {
+          formatter.format("%4d(%2d)", barcodeValue.getValue()[0],
+              barcodeValue.getConfidence(barcodeValue.getValue()[0]));
+        }
+      }
+      formatter.format("\n");
+    }
+    String result = formatter.toString();
+    formatter.close();
+    return result;
+  }
+
 }

core/src/com/google/zxing/pdf417/detector/Detector.java

@@ -38,8 +38,8 @@ import java.util.Map;
  */
 public final class Detector {
 
-  private static final int[] INDEXES_START_PATTERN = { 0, 4, 1, 5 };
+  private static final int[] INDEXES_START_PATTERN = {0, 4, 1, 5};
-  private static final int[] INDEXES_STOP_PATTERN = { 6, 2, 7, 3 };
+  private static final int[] INDEXES_STOP_PATTERN = {6, 2, 7, 3};
   private static final int INTEGER_MATH_SHIFT = 8;
   private static final int PATTERN_MATCH_RESULT_SCALE_FACTOR = 1 << INTEGER_MATH_SHIFT;
   private static final int MAX_AVG_VARIANCE = (int) (PATTERN_MATCH_RESULT_SCALE_FACTOR * 0.42f);
@@ -47,9 +47,9 @@ public final class Detector {
 
   // B S B S B S B S Bar/Space pattern
   // 11111111 0 1 0 1 0 1 000
-  private static final int[] START_PATTERN = { 8, 1, 1, 1, 1, 1, 1, 3 };
+  private static final int[] START_PATTERN = {8, 1, 1, 1, 1, 1, 1, 3};
   // 1111111 0 1 000 1 0 1 00 1
-  private static final int[] STOP_PATTERN = { 7, 1, 1, 3, 1, 1, 1, 2, 1 };
+  private static final int[] STOP_PATTERN = {7, 1, 1, 3, 1, 1, 1, 2, 1};
   private static final int MAX_PIXEL_DRIFT = 3;
   private static final int MAX_PATTERN_DRIFT = 5;
   // if we set the value too low, then we don't detect the correct height of the bar if the start patterns are damaged.
@@ -60,20 +60,7 @@ public final class Detector {
   private static final int ROW_STEP = 5;
   private static final int BARCODE_MIN_HEIGHT = 10;
 
-  private final BinaryBitmap image;
+  private Detector() {
-
-  public Detector(BinaryBitmap image) {
-    this.image = image;
-  }
-
-  /**
-   * <p>Detects a PDF417 Code in an image, simply.</p>
-   *
-   * @return {@link PDF417DetectorResult} encapsulating results of detecting a PDF417 Code
-   * @throws NotFoundException if no PDF417 Code can be found
-   */
-  public PDF417DetectorResult detect(boolean multiple) throws NotFoundException {
-    return detect(null, multiple);
   }
 
   /**
@@ -85,7 +72,8 @@ public final class Detector {
    * @return {@link PDF417DetectorResult} encapsulating results of detecting a PDF417 code
    * @throws NotFoundException if no PDF417 Code can be found
    */
-  PDF417DetectorResult detect(Map<DecodeHintType,?> hints, boolean multiple) throws NotFoundException {
+  public static PDF417DetectorResult detect(BinaryBitmap image, Map<DecodeHintType,?> hints, boolean multiple)
+      throws NotFoundException {
     // TODO detection improvement, tryHarder could try several different luminance thresholds/blackpoints or even 
     // different binarizers
     //boolean tryHarder = hints != null && hints.containsKey(DecodeHintType.TRY_HARDER);
@@ -107,12 +95,12 @@ public final class Detector {
    * @param bitMatrix bit matrix to detect barcodes in
    * @return List of ResultPoint arrays containing the coordinates of found barcodes
    */
-  private List<ResultPoint[]> detect(boolean multiple, BitMatrix bitMatrix) {
+  private static List<ResultPoint[]> detect(boolean multiple, BitMatrix bitMatrix) {
     List<ResultPoint[]> barcodeCoordinates = new ArrayList<ResultPoint[]>();
     int row = 0;
     int column = 0;
     boolean foundBarcodeInRow = false;
-    while (row < image.getHeight()) {
+    while (row < bitMatrix.getHeight()) {
       ResultPoint[] vertices = findVertices(bitMatrix, row, column);
 
       if (vertices[0] == null && vertices[3] == null) {
@@ -224,8 +212,12 @@ public final class Detector {
     }
   }
 
-  private static ResultPoint[] findRowsWithPattern(BitMatrix matrix, int height, int width, int startRow,
+  private static ResultPoint[] findRowsWithPattern(BitMatrix matrix,
-                                                   int startColumn, int[] pattern) {
+                                                   int height,
+                                                   int width,
+                                                   int startRow,
+                                                   int startColumn,
+                                                   int[] pattern) {
     ResultPoint[] result = new ResultPoint[4];
     boolean found = false;
     int[] counters = new int[pattern.length];
@@ -251,14 +243,15 @@ public final class Detector {
     // Last row of the current symbol that contains pattern
     if (found) {
       int skippedRowCount = 0;
-      int[] previousRowLoc = { (int) result[0].getX(), (int) result[1].getX() };
+      int[] previousRowLoc = {(int) result[0].getX(), (int) result[1].getX()};
       for (; stopRow < height; stopRow++) {
         int[] loc = findGuardPattern(matrix, previousRowLoc[0], stopRow, width, false, pattern, counters);
         // a found pattern is only considered to belong to the same barcode if the start and end positions
         // don't differ too much. Pattern drift should be not bigger than two for consecutive rows. With
         // a higher number of skipped rows drift could be larger. To keep it simple for now, we allow a slightly
         // larger drift and don't check for skipped rows.
-        if (loc != null && Math.abs(previousRowLoc[0] - loc[0]) < MAX_PATTERN_DRIFT &&
+        if (loc != null &&
+            Math.abs(previousRowLoc[0] - loc[0]) < MAX_PATTERN_DRIFT &&
             Math.abs(previousRowLoc[1] - loc[1]) < MAX_PATTERN_DRIFT) {
           previousRowLoc = loc;
           skippedRowCount = 0;
@@ -270,7 +263,7 @@ public final class Detector {
           }
         }
       }
-      stopRow -= skippedRowCount;
+      stopRow -= skippedRowCount + 1;
       result[2] = new ResultPoint(previousRowLoc[0], stopRow);
       result[3] = new ResultPoint(previousRowLoc[1], stopRow);
     }
@@ -292,8 +285,13 @@ public final class Detector {
    * @param counters array of counters, as long as pattern, to re-use 
    * @return start/end horizontal offset of guard pattern, as an array of two ints.
    */
-  private static int[] findGuardPattern(BitMatrix matrix, int column, int row, int width, boolean whiteFirst,
+  private static int[] findGuardPattern(BitMatrix matrix,
-                                        int[] pattern, int[] counters) {
+                                        int column,
+                                        int row,
+                                        int width,
+                                        boolean whiteFirst,
+                                        int[] pattern,
+                                        int[] counters) {
     Arrays.fill(counters, 0, counters.length, 0);
     int patternLength = pattern.length;
     boolean isWhite = whiteFirst;
@@ -313,7 +311,7 @@ public final class Detector {
       } else {
         if (counterPosition == patternLength - 1) {
           if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE) {
-            return new int[] { patternStart, x };
+            return new int[] {patternStart, x};
           }
           patternStart += counters[0] + counters[1];
           System.arraycopy(counters, 2, counters, 0, patternLength - 2);
@@ -329,7 +327,7 @@ public final class Detector {
     }
     if (counterPosition == patternLength - 1) {
       if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE) {
-        return new int[] { patternStart, x - 1 };
+        return new int[] {patternStart, x - 1};
       }
     }
     return null;

core/test/src/com/google/zxing/common/AbstractBlackBoxTestCase.java

@@ -296,7 +296,7 @@ public abstract class AbstractBlackBoxTestCase extends Assert {
     return true;
   }
 
-  private static String readFileAsString(File file, Charset charset) throws IOException {
+  protected static String readFileAsString(File file, Charset charset) throws IOException {
     StringBuilder result = new StringBuilder((int) file.length());
     InputStreamReader reader = new InputStreamReader(new FileInputStream(file), charset);
     try {

core/test/src/com/google/zxing/common/TestResult.java

@@ -16,7 +16,7 @@
 
 package com.google.zxing.common;
 
-final class TestResult {
+public final class TestResult {
 
   private final int mustPassCount;
   private final int tryHarderCount;
@@ -24,7 +24,7 @@ final class TestResult {
   private final int maxTryHarderMisreads;
   private final float rotation;
 
-  TestResult(int mustPassCount, int tryHarderCount, int maxMisreads, int maxTryHarderMisreads, float rotation) {
+  public TestResult(int mustPassCount, int tryHarderCount, int maxMisreads, int maxTryHarderMisreads, float rotation) {
     this.mustPassCount = mustPassCount;
     this.tryHarderCount = tryHarderCount;
     this.maxMisreads = maxMisreads;
@@ -32,23 +32,23 @@ final class TestResult {
     this.rotation = rotation;
   }
 
-  int getMustPassCount() {
+  public int getMustPassCount() {
     return mustPassCount;
   }
 
-  int getTryHarderCount() {
+  public int getTryHarderCount() {
     return tryHarderCount;
   }
   
-  int getMaxMisreads() {
+  public int getMaxMisreads() {
     return maxMisreads;
   }
   
-  int getMaxTryHarderMisreads() {
+  public int getMaxTryHarderMisreads() {
     return maxTryHarderMisreads;
   }
 
-  float getRotation() {
+  public float getRotation() {
     return rotation;
   }
 

core/test/src/com/google/zxing/pdf417/PDF417BlackBox2TestCase.java

@@ -29,9 +29,8 @@ public final class PDF417BlackBox2TestCase extends AbstractBlackBoxTestCase {
 
   public PDF417BlackBox2TestCase() {
     super("test/data/blackbox/pdf417-2", new MultiFormatReader(), BarcodeFormat.PDF_417);
-    // TODO this should be 25,25,0,0
+    addTest(25, 25, 0, 0, 0.0f);
-    addTest(23, 23, 1, 1, 0.0f);
+    addTest(25, 25, 0, 0, 180.0f);
-    addTest(23, 23, 1, 1, 180.0f);
   }
 
 }

core/test/src/com/google/zxing/pdf417/PDF417BlackBox4TestCase.java

@@ -0,0 +1,237 @@
+/*
+ * Copyright 2013 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.pdf417;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.BinaryBitmap;
+import com.google.zxing.BufferedImageLuminanceSource;
+import com.google.zxing.DecodeHintType;
+import com.google.zxing.LuminanceSource;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.ResultMetadataType;
+import com.google.zxing.common.AbstractBlackBoxTestCase;
+import com.google.zxing.common.HybridBinarizer;
+import com.google.zxing.common.SummaryResults;
+import com.google.zxing.common.TestResult;
+
+import org.junit.Test;
+
+import javax.imageio.ImageIO;
+
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.logging.Logger;
+
+/**
+ * This class tests Macro PDF417 barcode specific functionality. It ensures that information, which is split into
+ * several barcodes can be properly combined again to yield the original data content.
+ * 
+ * @author Guenther Grau
+ *
+ */
+public final class PDF417BlackBox4TestCase extends AbstractBlackBoxTestCase {
+  private static final Logger log = Logger.getLogger(AbstractBlackBoxTestCase.class.getSimpleName());
+
+  private static final Charset UTF8 = Charset.forName("UTF-8");
+  private static final Charset ISO88591 = Charset.forName("ISO-8859-1");
+  private static final String TEST_BASE_PATH_SUFFIX = "test/data/blackbox/pdf417-4";
+  private final PDF417Reader barcodeReader = new PDF417Reader();
+
+  private final List<TestResult> testResults = new ArrayList<TestResult>();
+  private File testBase;
+
+  public PDF417BlackBox4TestCase() {
+    super(TEST_BASE_PATH_SUFFIX, null, BarcodeFormat.PDF_417);
+    // A little workaround to prevent aggravation in my IDE
+    testBase = new File(TEST_BASE_PATH_SUFFIX);
+    if (!testBase.exists()) {
+      // try starting with 'core' since the test base is often given as the project root
+      testBase = new File("core/" + TEST_BASE_PATH_SUFFIX);
+    }
+    testResults.add(new TestResult(2, 2, 0, 0, 0.0f));
+  }
+
+  @Test
+  @Override
+  public void testBlackBox() throws IOException {
+    testPDF417BlackBoxCountingResults(true);
+  }
+
+  public SummaryResults testPDF417BlackBoxCountingResults(boolean assertOnFailure) throws IOException {
+    assertFalse(testResults.isEmpty());
+
+    Map<String,List<File>> imageFiles = getImageFileLists();
+    int testCount = testResults.size();
+
+    int[] passedCounts = new int[testCount];
+    int[] misreadCounts = new int[testCount];
+    int[] tryHarderCounts = new int[testCount];
+    int[] tryHaderMisreadCounts = new int[testCount];
+
+    for (Entry<String,List<File>> testImageGroup : imageFiles.entrySet()) {
+      log.fine(String.format("Starting Image Group %s", testImageGroup.getKey()));
+
+      String fileBaseName = testImageGroup.getKey();
+      String expectedText = null;
+      File expectedTextFile = new File(testBase, fileBaseName + ".txt");
+      if (expectedTextFile.exists()) {
+        expectedText = readFileAsString(expectedTextFile, UTF8);
+      } else {
+        expectedTextFile = new File(testBase, fileBaseName + ".bin");
+        assertTrue(expectedTextFile.exists());
+        expectedText = readFileAsString(expectedTextFile, ISO88591);
+      }
+
+      for (int x = 0; x < testCount; x++) {
+        List<Result> results = new ArrayList<Result>();
+        for (File imageFile : testImageGroup.getValue()) {
+          BufferedImage image = ImageIO.read(imageFile);
+          float rotation = testResults.get(x).getRotation();
+          BufferedImage rotatedImage = rotateImage(image, rotation);
+          LuminanceSource source = new BufferedImageLuminanceSource(rotatedImage);
+          BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
+
+          try {
+            results.addAll(Arrays.asList(decode(bitmap, false)));
+          } catch (ReaderException ignored) {
+            // ignore
+          }
+        }
+        Collections.sort(results, new Comparator<Result>() {
+          @Override
+          public int compare(Result arg0, Result arg1) {
+            PDF417ResultMetadata resultMetadata = getMeta(arg0);
+            PDF417ResultMetadata otherResultMetadata = getMeta(arg1);
+            return resultMetadata.getSegmentIndex() - otherResultMetadata.getSegmentIndex();
+          }
+        });
+        StringBuilder resultText = new StringBuilder();
+        String fileId = null;
+        for (Result result : results) {
+          PDF417ResultMetadata resultMetadata = getMeta(result);
+          assertNotNull("resultMetadata", resultMetadata);
+          if (fileId == null) {
+            fileId = resultMetadata.getFileId();
+          }
+          assertEquals("FileId", fileId, resultMetadata.getFileId());
+          resultText.append(result.getText());
+        }
+        assertEquals("ExpectedText", expectedText, resultText.toString());
+        passedCounts[x]++;
+        tryHarderCounts[x]++;
+      }
+    }
+
+    // Print the results of all tests first
+    int totalFound = 0;
+    int totalMustPass = 0;
+    int totalMisread = 0;
+    int totalMaxMisread = 0;
+
+    int numberOfTests = imageFiles.keySet().size();
+    for (int x = 0; x < testResults.size(); x++) {
+      TestResult testResult = testResults.get(x);
+      log.info(String.format("Rotation %d degrees:", (int) testResult.getRotation()));
+      log.info(String.format(" %d of %d images passed (%d required)", passedCounts[x], numberOfTests,
+          testResult.getMustPassCount()));
+      int failed = numberOfTests - passedCounts[x];
+      log.info(String
+          .format(" %d failed due to misreads, %d not detected", misreadCounts[x], failed - misreadCounts[x]));
+      log.info(String.format(" %d of %d images passed with try harder (%d required)", tryHarderCounts[x],
+          numberOfTests, testResult.getTryHarderCount()));
+      failed = numberOfTests - tryHarderCounts[x];
+      log.info(String.format(" %d failed due to misreads, %d not detected", tryHaderMisreadCounts[x], failed -
+          tryHaderMisreadCounts[x]));
+      totalFound += passedCounts[x] + tryHarderCounts[x];
+      totalMustPass += testResult.getMustPassCount() + testResult.getTryHarderCount();
+      totalMisread += misreadCounts[x] + tryHaderMisreadCounts[x];
+      totalMaxMisread += testResult.getMaxMisreads() + testResult.getMaxTryHarderMisreads();
+    }
+
+    int totalTests = numberOfTests * testCount * 2;
+    log.info(String.format("Decoded %d images out of %d (%d%%, %d required)", totalFound, totalTests, totalFound *
+        100 /
+        totalTests, totalMustPass));
+    if (totalFound > totalMustPass) {
+      log.warning(String.format("+++ Test too lax by %d images", totalFound - totalMustPass));
+    } else if (totalFound < totalMustPass) {
+      log.warning(String.format("--- Test failed by %d images", totalMustPass - totalFound));
+    }
+
+    if (totalMisread < totalMaxMisread) {
+      log.warning(String.format("+++ Test expects too many misreads by %d images", totalMaxMisread - totalMisread));
+    } else if (totalMisread > totalMaxMisread) {
+      log.warning(String.format("--- Test had too many misreads by %d images", totalMisread - totalMaxMisread));
+    }
+
+    // Then run through again and assert if any failed
+    if (assertOnFailure) {
+      for (int x = 0; x < testCount; x++) {
+        TestResult testResult = testResults.get(x);
+        String label = "Rotation " + testResult.getRotation() + " degrees: Too many images failed";
+        assertTrue(label, passedCounts[x] >= testResult.getMustPassCount());
+        assertTrue("Try harder, " + label, tryHarderCounts[x] >= testResult.getTryHarderCount());
+        label = "Rotation " + testResult.getRotation() + " degrees: Too many images misread";
+        assertTrue(label, misreadCounts[x] <= testResult.getMaxMisreads());
+        assertTrue("Try harder, " + label, tryHaderMisreadCounts[x] <= testResult.getMaxTryHarderMisreads());
+      }
+    }
+    return new SummaryResults(totalFound, totalMustPass, totalTests);
+  }
+
+  private static PDF417ResultMetadata getMeta(Result result) {
+    return result.getResultMetadata() == null ? null : (PDF417ResultMetadata) result.getResultMetadata().get(
+        ResultMetadataType.PDF417_EXTRA_METADATA);
+  }
+
+  private Result[] decode(BinaryBitmap source, boolean tryHarder) throws ReaderException {
+    Map<DecodeHintType,Object> hints = new EnumMap<DecodeHintType,Object>(DecodeHintType.class);
+    if (tryHarder) {
+      hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
+    }
+
+    return barcodeReader.decodeMultiple(source, hints);
+  }
+
+  private Map<String,List<File>> getImageFileLists() {
+    Map<String,List<File>> result = new HashMap<String,List<File>>();
+    for (File file : getImageFiles()) {
+      String testImageFileName = file.getName();
+      String fileBaseName = testImageFileName.substring(0, testImageFileName.indexOf('-'));
+      List<File> files = result.get(fileBaseName);
+      if (files == null) {
+        files = new ArrayList<File>();
+        result.put(fileBaseName, files);
+      }
+      files.add(file);
+    }
+    return result;
+  }
+
+}

core/test/src/com/google/zxing/pdf417/decoder/ec/ErrorCorrectionTestCase.java

@@ -17,6 +17,7 @@
 package com.google.zxing.pdf417.decoder.ec;
 
 import com.google.zxing.ChecksumException;
+
 import org.junit.Test;
 
 import java.util.Random;
@@ -32,25 +33,16 @@ public final class ErrorCorrectionTestCase extends AbstractErrorCorrectionTestCa
   //private static final int[] PDF417_TEST_WITH_EC =
   //    { 5, 453, 178, 121, 239, 452, 327, 657, 619 };
 
-  private static final int[] PDF417_TEST =
+  private static final int[] PDF417_TEST = {
-      { 48,901, 56,141,627,856,330, 69,244,900,
+      48, 901, 56, 141, 627, 856, 330, 69, 244, 900, 852, 169, 843, 895, 852, 895, 913, 154, 845, 778, 387, 89, 869,
-       852,169,843,895,852,895,913,154,845,778,
+      901, 219, 474, 543, 650, 169, 201, 9, 160, 35, 70, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900,
-       387, 89,869,901,219,474,543,650,169,201,
+      900, 900};
-         9,160, 35, 70,900,900,900,900,900,900,
+  private static final int[] PDF417_TEST_WITH_EC = {
-       900,900,900,900,900,900,900,900};
+      48, 901, 56, 141, 627, 856, 330, 69, 244, 900, 852, 169, 843, 895, 852, 895, 913, 154, 845, 778, 387, 89, 869,
-  private static final int[] PDF417_TEST_WITH_EC =
+      901, 219, 474, 543, 650, 169, 201, 9, 160, 35, 70, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900, 900,
-      { 48,901, 56,141,627,856,330, 69,244,900,
+      900, 900, 769, 843, 591, 910, 605, 206, 706, 917, 371, 469, 79, 718, 47, 777, 249, 262, 193, 620, 597, 477, 450,
-       852,169,843,895,852,895,913,154,845,778,
+      806, 908, 309, 153, 871, 686, 838, 185, 674, 68, 679, 691, 794, 497, 479, 234, 250, 496, 43, 347, 582, 882, 536,
-       387, 89,869,901,219,474,543,650,169,201,
+      322, 317, 273, 194, 917, 237, 420, 859, 340, 115, 222, 808, 866, 836, 417, 121, 833, 459, 64, 159};
-         9,160, 35, 70,900,900,900,900,900,900,
-       900,900,900,900,900,900,900,900,769,843,
-       591,910,605,206,706,917,371,469, 79,718,
-        47,777,249,262,193,620,597,477,450,806,
-       908,309,153,871,686,838,185,674, 68,679,
-       691,794,497,479,234,250,496, 43,347,582,
-       882,536,322,317,273,194,917,237,420,859,
-       340,115,222,808,866,836,417,121,833,459,
-        64,159};
   private static final int ECC_BYTES = PDF417_TEST_WITH_EC.length - PDF417_TEST.length;
   // Example is EC level 1 (s=1). The number of erasures (l) and substitutions (f) must obey:
   // l + 2f <= 2^(s+1) - 3
@@ -81,7 +73,7 @@ public final class ErrorCorrectionTestCase extends AbstractErrorCorrectionTestCa
   @Test
   public void testMaxErrors() throws ChecksumException {
     Random random = getRandom();
-    for (int test : PDF417_TEST) { // # iterations is kind of arbitrary
+    for (int testIterations = 0; testIterations < 100; testIterations++) { // # iterations is kind of arbitrary
       int[] received = PDF417_TEST_WITH_EC.clone();
       corrupt(received, MAX_ERRORS, random);
       checkDecode(received);
@@ -137,4 +129,4 @@ public final class ErrorCorrectionTestCase extends AbstractErrorCorrectionTestCa
     }
   }
 
-}
+}