title: How to access pixel values of CV_32F/CV_64F Mat?
body: <p>I was working on homography and whenever I try to check the values of H matrix (type CV_64F) using <code>H.at&lt;float&gt;(i, j)</code> I get random numbers(sometimes garbage value). I want to access pixel values of float matrix. Is there any way to do it?</p>
  
  <pre><code>Mat A = Mat::eye(3, 3, CV_64F);
  float B;
  for(int i=0; i&lt;A.rows; i++)
  {
      for(int j=0; j&lt;A.cols; j++)
      {
          printf("%f\n", A.at&lt;float&gt;(i, j));
      }
  }
  
  imshow("identity", A);
  waitKey(0);
  </code></pre>
  
  <p>This shows correct image of an identity matrix but while trying to access pixel values, I get</p>
  
  <blockquote>
    <p>0.000000
    1.875000
    0.000000
    0.000000
    0.000000
    0.000000
    0.000000
    0.000000
    0.000000</p>
  </blockquote>
  
  <p>Why is this so?</p>