title: OpenCV Template Matching example in Android
body: <p>I'm a beginner to OpenCV. I'm trying to do a sample android application to match a template image in a given image using OpenCV Template matching. I searched in the internet and I couldn't find a proper android or java code which satisfy my requirement. But I have C++ code. I dont know how to translate it.
  <a href="http://docs.opencv.org/doc/tutorials/imgproc/histograms/template_matching/template_matching.html" rel="noreferrer">http://docs.opencv.org/doc/tutorials/imgproc/histograms/template_matching/template_matching.html</a></p>
  
  <p>Can you please help me to find a proper java or android code. Or else please help me with translate this C++ code into java, which I can use inside android application.</p>
  
  <p>Thank you in advance.</p>
  
  <p>C++ code</p>
  
  <pre><code>#include "opencv2/highgui/highgui.hpp"
  #include "opencv2/imgproc/imgproc.hpp"
  #include &lt;iostream&gt;
  #include &lt;stdio.h&gt;
  
  using namespace std;
  using namespace cv;
  
  /// Global Variables
  Mat img; Mat templ; Mat result;
  char* image_window = "Source Image";
  char* result_window = "Result window";
  
  int match_method;
  int max_Trackbar = 5;
  
  /// Function Headers
  void MatchingMethod( int, void* );
  
  /** @function main */
  int main( int argc, char** argv )
  {
    /// Load image and template
    img = imread( argv[1], 1 );
    templ = imread( argv[2], 1 );
  
    /// Create windows
    namedWindow( image_window, CV_WINDOW_AUTOSIZE );
    namedWindow( result_window, CV_WINDOW_AUTOSIZE );
  
    /// Create Trackbar
    char* trackbar_label = "Method: \n 0: SQDIFF \n 1: SQDIFF NORMED \n 2: TM CCORR \n 3: TM CCORR NORMED \n 4: TM COEFF \n 5: TM COEFF NORMED";
    createTrackbar( trackbar_label, image_window, &amp;match_method, max_Trackbar, MatchingMethod );
  
    MatchingMethod( 0, 0 );
  
    waitKey(0);
    return 0;
  }
  
  /**
   * @function MatchingMethod
   * @brief Trackbar callback
   */
  void MatchingMethod( int, void* )
  {
    /// Source image to display
    Mat img_display;
    img.copyTo( img_display );
  
    /// Create the result matrix
    int result_cols =  img.cols - templ.cols + 1;
    int result_rows = img.rows - templ.rows + 1;
  
    result.create( result_cols, result_rows, CV_32FC1 );
  
    /// Do the Matching and Normalize
    matchTemplate( img, templ, result, match_method );
    normalize( result, result, 0, 1, NORM_MINMAX, -1, Mat() );
  
    /// Localizing the best match with minMaxLoc
    double minVal; double maxVal; Point minLoc; Point maxLoc;
    Point matchLoc;
  
    minMaxLoc( result, &amp;minVal, &amp;maxVal, &amp;minLoc, &amp;maxLoc, Mat() );
  
    /// For SQDIFF and SQDIFF_NORMED, the best matches are lower values. For all the other methods, the higher the better
    if( match_method  == CV_TM_SQDIFF || match_method == CV_TM_SQDIFF_NORMED )
      { matchLoc = minLoc; }
    else
      { matchLoc = maxLoc; }
  
    /// Show me what you got
    rectangle( img_display, matchLoc, Point( matchLoc.x + templ.cols , matchLoc.y + templ.rows ), Scalar::all(0), 2, 8, 0 );
    rectangle( result, matchLoc, Point( matchLoc.x + templ.cols , matchLoc.y + templ.rows ), Scalar::all(0), 2, 8, 0 );
  
    imshow( image_window, img_display );
    imshow( result_window, result );
  
    return;
  }
  </code></pre>