Java API: added tests for FlannBased DescriptorMatcher

modules/java/android_test/src/org/opencv/test/features2d/FlannBasedDescriptorMatcherTest.java

+package org.opencv.test.features2d;
+
+import org.opencv.core.Core;
+import org.opencv.core.CvException;
+import org.opencv.core.CvType;
+import org.opencv.core.Mat;
+import org.opencv.core.Point;
+import org.opencv.core.Scalar;
+import org.opencv.features2d.DMatch;
+import org.opencv.features2d.DescriptorExtractor;
+import org.opencv.features2d.DescriptorMatcher;
+import org.opencv.features2d.FeatureDetector;
+import org.opencv.features2d.KeyPoint;
+import org.opencv.test.OpenCVTestCase;
+import org.opencv.test.OpenCVTestRunner;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class FlannBasedDescriptorMatcherTest extends OpenCVTestCase {
+
+    DescriptorMatcher matcher;
+    int matSize;
+    DMatch[] truth;
+
+    protected void setUp() throws Exception {
+        matcher = DescriptorMatcher.create(DescriptorMatcher.FLANNBASED);
+        matSize = 100;
+
+        truth = new DMatch[] { 
+                new DMatch(0, 0, 0, 0.643284f),
+                new DMatch(1, 1, 0, 0.92945856f),
+                new DMatch(2, 1, 0, 0.2841479f),
+                new DMatch(3, 1, 0, 0.9194034f),
+                new DMatch(4, 1, 0, 0.3006621f) };
+
+        super.setUp();
+    }
+
+    private Mat getTrainImg() {
+        Mat cross = new Mat(matSize, matSize, CvType.CV_8U, new Scalar(255));
+        Core.line(cross, new Point(20, matSize / 2), new Point(matSize - 21, matSize / 2), new Scalar(100), 2);
+        Core.line(cross, new Point(matSize / 2, 20), new Point(matSize / 2, matSize - 21), new Scalar(100), 2);
+
+        return cross;
+    }
+
+    private Mat getQueryImg() {
+        Mat cross = new Mat(matSize, matSize, CvType.CV_8U, new Scalar(255));
+        Core.line(cross, new Point(30, matSize / 2), new Point(matSize - 31, matSize / 2), new Scalar(100), 3);
+        Core.line(cross, new Point(matSize / 2, 30), new Point(matSize / 2, matSize - 31), new Scalar(100), 3);
+
+        return cross;
+    }
+
+    private Mat getQueryDescriptors() {
+        Mat img = getQueryImg();
+        List<KeyPoint> keypoints = new ArrayList<KeyPoint>();
+        Mat descriptors = new Mat();
+
+        FeatureDetector detector = FeatureDetector.create(FeatureDetector.SURF);
+        DescriptorExtractor extractor = DescriptorExtractor.create(DescriptorExtractor.SURF);
+
+        String filename = OpenCVTestRunner.getTempFileName("yml");
+        writeFile(filename, "%YAML:1.0\nhessianThreshold: 8000.\noctaves: 3\noctaveLayers: 4\nupright: 0\n");
+        detector.read(filename);
+
+        detector.detect(img, keypoints);
+        extractor.compute(img, keypoints, descriptors);
+
+        return descriptors;
+    }
+
+    private Mat getTrainDescriptors() {
+        Mat img = getTrainImg();
+        List<KeyPoint> keypoints = Arrays.asList(new KeyPoint(50, 50, 16, 0, 20000, 1, -1), new KeyPoint(42, 42, 16, 160, 10000, 1, -1));
+        Mat descriptors = new Mat();
+
+        DescriptorExtractor extractor = DescriptorExtractor.create(DescriptorExtractor.SURF);
+
+        extractor.compute(img, keypoints, descriptors);
+
+        return descriptors;
+    }
+
+    private Mat getMaskImg() {
+        return new Mat(5, 2, CvType.CV_8U, new Scalar(0)) {
+            {
+                put(0,0, 1, 1, 1, 1);
+            }
+        };
+    }
+
+    public void testAdd() {
+        matcher.add(Arrays.asList(new Mat()));
+        assertFalse(matcher.empty());
+    }
+
+    public void testClear() {
+        matcher.add(Arrays.asList(new Mat()));
+
+        matcher.clear();
+
+        assertTrue(matcher.empty());
+    }
+
+    public void testCloneBoolean() {
+        matcher.add(Arrays.asList(new Mat()));
+
+        DescriptorMatcher cloned = matcher.clone(true);
+
+        assertNotNull(cloned);
+        assertTrue(cloned.empty());
+    }
+
+    public void testClone() {
+        Mat train = new Mat(1, 1, CvType.CV_8U, new Scalar(123));
+        matcher.add(Arrays.asList(train));
+
+        try {
+            matcher.clone();
+            fail("Expected CvException (CV_StsNotImplemented)");
+        } catch (CvException cverr) {
+            // expected
+        }
+    }
+
+    public void testCreate() {
+        assertNotNull(matcher);
+    }
+
+    public void testEmpty() {
+        assertTrue(matcher.empty());
+    }
+
+    public void testGetTrainDescriptors() {
+        Mat train = new Mat(1, 1, CvType.CV_8U, new Scalar(123));
+        Mat truth = train.clone();
+        matcher.add(Arrays.asList(train));
+
+        List<Mat> descriptors = matcher.getTrainDescriptors();
+
+        assertEquals(1, descriptors.size());
+        assertMatEqual(truth, descriptors.get(0));
+    }
+
+    public void testIsMaskSupported() {
+        assertFalse(matcher.isMaskSupported());
+    }
+
+    public void testMatchMatMatListOfDMatchMat() {
+        Mat train = getTrainDescriptors();
+        Mat query = getQueryDescriptors();
+        Mat mask = getMaskImg();
+        List<DMatch> matches = new ArrayList<DMatch>();
+        
+        matcher.match(query, train, matches, mask);
+
+        assertListDMatchEquals(Arrays.asList(truth), matches, EPS);
+    }
+
+    public void testMatchMatMatListOfDMatch() {
+        Mat train = getTrainDescriptors();
+        Mat query = getQueryDescriptors();
+        List<DMatch> matches = new ArrayList<DMatch>();
+        
+        matcher.match(query, train, matches);
+        
+        assertListDMatchEquals(Arrays.asList(truth), matches, EPS);
+
+//        OpenCVTestRunner.Log("matches found: " + matches.size());
+//        for (DMatch m : matches)
+//            OpenCVTestRunner.Log(m.toString());
+    }
+
+    public void testMatchMatListOfDMatchListOfMat() {
+        Mat train = getTrainDescriptors();
+        Mat query = getQueryDescriptors();
+        Mat mask = getMaskImg();
+        List<DMatch> matches = new ArrayList<DMatch>();
+        matcher.add(Arrays.asList(train));
+        matcher.train();
+
+        matcher.match(query, matches, Arrays.asList(mask));
+
+        assertListDMatchEquals(Arrays.asList(truth), matches, EPS);
+    }
+
+    public void testMatchMatListOfDMatch() {
+        Mat train = getTrainDescriptors();
+        Mat query = getQueryDescriptors();
+        List<DMatch> matches = new ArrayList<DMatch>();
+        matcher.add(Arrays.asList(train));
+        matcher.train();
+        
+        matcher.match(query, matches);
+        
+        assertListDMatchEquals(Arrays.asList(truth), matches, EPS);
+    }
+
+    public void testRead() {
+        fail("https://code.ros.org/trac/opencv/ticket/1253");
+        String filename = OpenCVTestRunner.getTempFileName("yml");
+        writeFile(filename, "%YAML:1.0\n");
+
+        matcher.read(filename);
+        assertTrue(true);
+    }
+
+    public void testTrain() {
+        Mat train = getTrainDescriptors();
+        matcher.add(Arrays.asList(train));
+        matcher.train();
+    }
+    
+    public void testTrainNoData() {
+        try {
+            matcher.train();
+            fail("Expected CvException - FlannBasedMatcher::train should fail on empty train set");
+        } catch (CvException cverr) {
+            // expected
+        }
+    }
+
+    public void testWrite() {
+        fail("https://code.ros.org/trac/opencv/ticket/1253");
+        String filename = OpenCVTestRunner.getTempFileName("yml");
+
+        matcher.write(filename);
+
+        String truth = "%YAML:1.0\n!!!!!";
+        assertEquals(truth, readFile(filename));
+    }
+
+}