title: Matcher Assertions failed error opencv Android
body: <p>I'm writing code to find similar object from drawable in camerapreview. I am using the newest Opencv 2.4.4.</p>
  
  <p>Below are my functions and an output from logcat. What am I doing wrong that I'm getting such output?</p>
  
  <pre><code> public void detect_image (Mat mRgba) {
  
      object_desc = new Mat();
      scene_desc = new Mat();
  
      object_keys = new MatOfKeyPoint();
      scene_keys = new MatOfKeyPoint();
  
      matches = new MatOfDMatch();
      good_matches = new MatOfDMatch();
  
      Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.sto);
      Utils.bitmapToMat(image,object);   
  
      surf = FeatureDetector.create(FeatureDetector.FAST);
      surf.detect( object, object_keys );   
      surf.detect( mRgba, scene_keys);
      surfEX = DescriptorExtractor.create(DescriptorExtractor.BRIEF);
      surfEX.compute(object, object_keys, object_desc);       
      surfEX.compute(mRgba, scene_keys, scene_desc);
      dm = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE_SL2);    
      dm.match(object_desc, scene_desc, matches);
  
      double max_dist = 0;
      double min_dist = 100;
  
      for( int i = 0; i &lt; object_desc.rows(); i++ )
        { double dist = matches.toArray()[i].distance;
          if( dist &lt; min_dist ) min_dist = dist;
          if( dist &gt; max_dist ) max_dist = dist;
        }
  
       for( int i = 0; i &lt; object_desc.rows(); i++ )
        {  MatOfDMatch temp = new MatOfDMatch();
           if( matches.toArray()[i].distance &lt; 3*min_dist )
           {   temp.fromArray(matches.toArray()[i]);
               good_matches.push_back(temp); 
               }        
        }
  
  }
  
  
  
  public Mat onCameraFrame(CvCameraViewFrame inputFrame) {        
       mRgba = inputFrame.rgba();
               detect_image(mRgba);
       return inputFrame.rgba();
  }
  </code></pre>
  
  <p>Logcat:</p>
  
  <pre><code>03-27 01:55:31.258: E/cv::error()(564): OpenCV Error: Assertion failed 
  (type == src2.type() &amp;&amp; src1.cols == src2.cols &amp;&amp; 
  (type == CV_32F || type == CV_8U)) in void cv::batchDistance(cv::InputArray,
  cv::InputArray, cv::OutputArray, int, cv::OutputArray, int, int, cv::InputArray,
  int,  bool), file /home/reports/ci/slave/50-SDK/opencv/modules/core/src/stat.cpp,
  line 1803
  </code></pre>