title: OpenCV FeatureDetector doesn't seem to set various properties after reading it from file
body: <p>Following is the code to detect blob/moles in colored skin image using Java and OpenCV 3.0</p>
  
  <pre><code>private void initLibService(){
  
      String opencvpath = System.getProperty("user.dir") + File.separator + "lib" + File.separator;
      System.load(opencvpath + Core.NATIVE_LIBRARY_NAME + ".dll");
  
      blobDetector = FeatureDetector.create(FeatureDetector.SIMPLEBLOB);
  
      try {
          File temp = File.createTempFile("tempFile",".tmp");
          String settings="%YAML:1.0\nthresholdStep: " + Integer.parseInt(ResourceUtil.getProperty("MOLE_THRESHOLD_STEPS")) + "\nminThreshold: "+ Integer.parseInt(ResourceUtil.getProperty("MOLE_UPPER_INTENSITY_THRESOLD")) + "\n";
          System.out.println("\nFeature detector setting data: " + settings + "\n\n");
  
          FileWriter writer=new FileWriter(temp,false);
          writer.write(settings);
          writer.close();
  
          blobDetector.read(temp.getPath());
  
          temp.deleteOnExit();
        }
       catch (  IOException e) {
          e.printStackTrace();
        }
      }
  
  public static Mat detectBlob(String imagePath, FeatureDetector blobDetector) {
  
      // Read image
      Mat im = Imgcodecs.imread(imagePath);
  
      MatOfKeyPoint keypoints = new MatOfKeyPoint();
  
      blobDetector.detect(im, keypoints);
      System.out.println("keypoints: " + keypoints.toList());
  
      Mat im_with_keypoints = new Mat();
      Features2d.drawKeypoints(im, keypoints, im_with_keypoints, new Scalar(0, 255, 0), Features2d.DRAW_RICH_KEYPOINTS);
  
      return im_with_keypoints;
  }
  </code></pre>
  
  <p>If I comment the line <code>blobDetector.read(temp.getPath());</code> then the attached skin image is being marked with circles around some moles (may be using some default property values of featuredetector), but If I didn't, nothing get marked on the image.</p>
  
  <p><a href="https://i.stack.imgur.com/ZdBvY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ZdBvY.png" alt="enter image description here"></a></p>