What to do with DMatch value ?

edit

I have this code for image matching using ORB

  FeatureDetector detector = FeatureDetector.create(FeatureDetector.ORB);
    DescriptorExtractor descriptor = DescriptorExtractor.create(DescriptorExtractor.ORB);;
    DescriptorMatcher matcher = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE_HAMMING);
    File root = Environment.getExternalStorageDirectory();
    File file = new File( root, "nano1.jpg");
    File file2 = new File( root, "nano2.jpg");
    Log.d(LOG_TAG, "File " + file.exists() + " & "+ file2.exists() + " " + root.getAbsolutePath());

    //first image
    Mat img1 = Highgui.imread(file.getAbsolutePath());
    Mat descriptors1 = new Mat();
    MatOfKeyPoint keypoints1 = new MatOfKeyPoint();

    detector.detect(img1, keypoints1);
    descriptor.compute(img1, keypoints1, descriptors1);

    //second image
    Mat img2 = Highgui.imread(file2.getAbsolutePath());
    Mat descriptors2 = new Mat();
    MatOfKeyPoint keypoints2 = new MatOfKeyPoint();

    detector.detect(img2, keypoints2);
    descriptor.compute(img2, keypoints2, descriptors2);


    //matcher should include 2 different image's descriptors
    MatOfDMatch  matches = new MatOfDMatch();             
    matcher.match(descriptors1,descriptors2,matches);
    Log.d(LOG_TAG, "size " + matches.size());

    //feature and connection colors
    Scalar RED = new Scalar(255,0,0);
    Scalar GREEN = new Scalar(0,255,0);
    //output image
    Mat outputImg = new Mat();
    MatOfByte drawnMatches = new MatOfByte();
    //this will draw all matches, works fine
    Features2d.drawMatches(img1, keypoints1, img2, keypoints2, matches, 
            outputImg, GREEN, RED,  drawnMatches, Features2d.NOT_DRAW_SINGLE_POINTS);
    int DIST_LIMIT = 80;
    List<DMatch> matchList = matches.toList();
    List<DMatch> matches_final = new ArrayList<DMatch>();
    for(int i=0; i<matchList.size(); i++){
        if(matchList.get(i).distance <= DIST_LIMIT){
            matches_final.add(matches.toList().get(i));
        }
    }

    MatOfDMatch matches_final_mat = new MatOfDMatch();
    matches_final_mat.fromList(matches_final);
    for(int i=0; i< matches_final.size(); i++){
        Log.d(LOG_TAG,""+ matches_final.get(i));
    }

And in the matches I get

08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=0, trainIdx=8, imgIdx=0, distance=63.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=1, trainIdx=81, imgIdx=0, distance=78.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=2, trainIdx=162, imgIdx=0, distance=73.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=3, trainIdx=189, imgIdx=0, distance=75.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=4, trainIdx=88, imgIdx=0, distance=77.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=5, trainIdx=89, imgIdx=0, distance=60.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=6, trainIdx=81, imgIdx=0, distance=78.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=7, trainIdx=68, imgIdx=0, distance=57.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=8, trainIdx=298, imgIdx=0, distance=48.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=9, trainIdx=12, imgIdx=0, distance=39.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=10, trainIdx=479, imgIdx=0, distance=66.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=11, trainIdx=480, imgIdx=0, distance=63.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=12, trainIdx=125, imgIdx=0, distance=56.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=13, trainIdx=298, imgIdx=0, distance=71.0]
08-08 14:59:29.569: D/FdActivity(9001): DMatch [queryIdx=14 ...