title: Emgu.CV.Util.CvException: 'OpenCV: i < 0' Exception
body: <p>I am new on EmguCV. I'm trying to '<em>DrawContours</em>' using the <code>CvInvoke.DrawContours()</code> method, but, when running I have the following exception:</p>
  <blockquote>
  <p>Emgu.CV.Util.CvException: 'OpenCV: i &lt; 0'</p>
  </blockquote>
  <p>The error code is</p>
  <pre><code>if (biggestCountor.Size != 0)
  {
       CvInvoke.DrawContours(imgBiggestContours, biggestCountor, -1, new MCvScalar(0, 255, 100), 20);
  }
  </code></pre>
  <p>The <code>biggestCountor</code> variable is a <code>VectorOfPoint</code> type and it's value is</p>
  <blockquote>
  <p>[234, 110]</p>
  <p>[174, 369]</p>
  <p>[601, 405]</p>
  </blockquote>
  <p>which represents the <code>Points</code> coordinates.</p>
  <p>I believe the error is with the <code>biggestCountor</code> variable, because, when replacing it for another variable of the same type, but with different values on this same code, it works.</p>
  <p>I am using the <em>EmguCV 4.5.1.4349</em> with <em>Visual Studio 2019</em>.</p>