title: IMAGE COMPARISON USING OPENCV code from poitr
body: <p>HI i found this code to compare images </p>
  
  <pre><code>cv::Mat img1 = ...
  cv::Mat img2 = ...
  cv::Mat result = ...
  
  int threshold = (double)(img1.rows * img1.cols) * 0.7; 
  
  cv::compare(img1 , img2  , result , cv::CMP_EQ );
  int similarPixels  = countNonZero(result);
  
  if ( similarPixels  &gt; threshold ) {
     cout &lt;&lt; "similar" &lt;&lt; endl;
  }
  </code></pre>
  
  <p>but since i m new to OPENCV i dont know what are the values for " cv::Mat img1=..."
  please help me out and tried out the code with the image path as value but its giving an error</p>