Reworked the false positives unit tests to track each rotation separately, and to allow new tests to be added. I also removed four images which are going to live in another test.

git-svn-id: https://zxing.googlecode.com/svn/trunk@475 59b500cc-1b3d-0410-9834-0bbf25fbcc57

core/build.xml

@@ -139,6 +139,7 @@
         <fileset dir="test/src">
           <include name="**/*BlackBox*TestCase.java"/>
           <exclude name="com/google/zxing/common/AbstractBlackBoxTestCase.java"/>
+          <exclude name="com/google/zxing/common/AbstractNegativeBlackBoxTestCase.java"/>
         </fileset>
       </batchtest>
     </junit>

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

@@ -0,0 +1,129 @@
+/*
+ * Copyright 2008 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.common;
+
+import com.google.zxing.MonochromeBitmapSource;
+import com.google.zxing.MultiFormatReader;
+import com.google.zxing.ReaderException;
+import com.google.zxing.Result;
+import com.google.zxing.client.j2se.BufferedImageMonochromeBitmapSource;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.util.Vector;
+
+/**
+ * This abstract class looks for negative results, i.e. it only allows a certain number of false
+ * positives in images which should not decode. This helps ensure that we are not too lenient.
+ *
+ * @author dswitkin@google.com (Daniel Switkin)
+ */
+public abstract class AbstractNegativeBlackBoxTestCase extends AbstractBlackBoxTestCase {
+
+  private static class TestResult {
+    private final int falsePositivesAllowed;
+    private final float rotation;
+
+    TestResult(int falsePositivesAllowed, float rotation) {
+      this.falsePositivesAllowed = falsePositivesAllowed;
+      this.rotation = rotation;
+    }
+
+    public int getFalsePositivesAllowed() {
+      return falsePositivesAllowed;
+    }
+
+    public float getRotation() {
+      return rotation;
+    }
+  }
+
+  private Vector<TestResult> testResults;
+
+  // Use the multiformat reader to evaluate all decoders in the system.
+  protected AbstractNegativeBlackBoxTestCase(File testBase) {
+    super(testBase, new MultiFormatReader(), null);
+    testResults = new Vector<TestResult>();
+  }
+
+  protected void addTest(int falsePositivesAllowed, float rotation) {
+    testResults.add(new TestResult(falsePositivesAllowed, rotation));
+  }
+
+  @Override
+  public void testBlackBox() throws IOException {
+    assertFalse(testResults.isEmpty());
+
+    File[] imageFiles = getImageFiles();
+    int[] falsePositives = new int[testResults.size()];
+    for (File testImage : imageFiles) {
+      System.out.println("Starting " + testImage.getAbsolutePath());
+
+      BufferedImage image = ImageIO.read(testImage);
+      if (image == null) {
+        throw new IOException("Could not read image: " + testImage);
+      }
+      for (int x = 0; x < testResults.size(); x++) {
+        if (!checkForFalsePositives(image, testResults.get(x).getRotation())) {
+          falsePositives[x]++;
+        }
+      }
+    }
+
+    for (int x = 0; x < testResults.size(); x++) {
+      System.out.println("Rotation " + testResults.get(x).getRotation() + " degrees: " +
+          falsePositives[x] + " of " + imageFiles.length + " images were false positives (" +
+          testResults.get(x).getFalsePositivesAllowed() + " allowed)");
+      assertTrue("Rotation " + testResults.get(x).getRotation() + " degrees: " +
+          "Too many false positives found",
+          falsePositives[x] <= testResults.get(x).getFalsePositivesAllowed());
+    }
+  }
+
+  /**
+   * Make sure ZXing does NOT find a barcode in the image.
+   *
+   * @param image The image to test
+   * @param rotationInDegrees The amount of rotation to apply
+   * @return true if nothing found, false if a non-existant barcode was detected
+   */
+  private boolean checkForFalsePositives(BufferedImage image, float rotationInDegrees) {
+    BufferedImage rotatedImage = rotateImage(image, rotationInDegrees);
+    MonochromeBitmapSource source = new BufferedImageMonochromeBitmapSource(rotatedImage);
+    Result result;
+    try {
+      result = getReader().decode(source);
+      System.out.println("Found false positive: '" + result.getText() + "' with format '" +
+          result.getBarcodeFormat() + "' (rotation: " + rotationInDegrees + ')');
+      return false;
+    } catch (ReaderException re) {
+    }
+
+    // Try "try harder" mode
+    try {
+      result = getReader().decode(source, TRY_HARDER_HINT);
+      System.out.println("Try harder found false positive: '" + result.getText() + "' with format '" +
+          result.getBarcodeFormat() + "' (rotation: " + rotationInDegrees + ')');
+      return false;
+    } catch (ReaderException re) {
+    }
+    return true;
+  }
+
+}

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

@@ -16,85 +16,21 @@
 
 package com.google.zxing.common;
 
-import com.google.zxing.MonochromeBitmapSource;
-import com.google.zxing.MultiFormatReader;
-import com.google.zxing.ReaderException;
-import com.google.zxing.Result;
-import com.google.zxing.client.j2se.BufferedImageMonochromeBitmapSource;
-
-import javax.imageio.ImageIO;
-import java.awt.image.BufferedImage;
 import java.io.File;
-import java.io.IOException;
 
 /**
- * This test ensures that random, noisy, or unsupported barcode images do not decode.
+ * This test ensures that random images with high contrast patterns do not decode as barcodes.
  *
  * @author dswitkin@google.com (Daniel Switkin)
  */
-public final class FalsePositivesBlackBoxTestCase extends AbstractBlackBoxTestCase {
+public final class FalsePositivesBlackBoxTestCase extends AbstractNegativeBlackBoxTestCase {
 
-  // This number should be reduced as we get better at rejecting false positives.
-  private static final int FALSE_POSITIVES_ALLOWED = 4;
-
-  // Use the multiformat reader to evaluate all decoders in the system.
   public FalsePositivesBlackBoxTestCase() {
-    super(new File("test/data/blackbox/falsepositives"), new MultiFormatReader(), null);
+    super(new File("test/data/blackbox/falsepositives"));
-  }
+    addTest(1, 0.0f);
-
+    addTest(1, 90.0f);
-  @Override
+    addTest(1, 180.0f);
-  public void testBlackBox() throws IOException {
+    addTest(0, 270.0f);
-    File[] imageFiles = getImageFiles();
-    int falsePositives = 0;
-    for (File testImage : imageFiles) {
-      System.out.println("Starting " + testImage.getAbsolutePath());
-
-      // Try all four rotations, since many of the test images don't have a notion of up, and we
-      // want to be as robust as possible.
-      BufferedImage image = ImageIO.read(testImage);
-      if (image == null) {
-        throw new IOException("Could not read image: " + testImage);
-      }
-      for (int x = 0; x < 4; x++) {
-        if (!checkForFalsePositives(image, x * 90.0f)) {
-          falsePositives++;
-        }
-      }
-    }
-
-    System.out.println("Found " + falsePositives + " false positives (" + FALSE_POSITIVES_ALLOWED +
-        " max)");
-    assertTrue("Too many false positives found", falsePositives <= FALSE_POSITIVES_ALLOWED);
-  }
-
-  /**
-   * Make sure ZXing does NOT find a barcode in the image.
-   *
-   * @param image The image to test
-   * @param rotationInDegrees The amount of rotation to apply
-   * @return true if nothing found, false if a non-existant barcode was detected
-   */
-  private boolean checkForFalsePositives(BufferedImage image, float rotationInDegrees) {
-    BufferedImage rotatedImage = rotateImage(image, rotationInDegrees);
-    MonochromeBitmapSource source = new BufferedImageMonochromeBitmapSource(rotatedImage);
-    Result result;
-    try {
-      result = getReader().decode(source);
-      System.out.println("Found false positive: '" + result.getText() + "' with format '" +
-          result.getBarcodeFormat() + "' (rotation: " + rotationInDegrees + ')');
-      return false;
-    } catch (ReaderException re) {
-    }
-
-    // Try "try harder" mode
-    try {
-      result = getReader().decode(source, TRY_HARDER_HINT);
-      System.out.println("Try harder found false positive: '" + result.getText() + "' with format '" +
-          result.getBarcodeFormat() + "' (rotation: " + rotationInDegrees + ')');
-      return false;
-    } catch (ReaderException re) {
-    }
-    return true;
   }
 
 }