title: Combine multiple images in Emgu or opencv
body: <p>I have lots of colors ranges need to filter then combine achieved images to get single image contained all those filtered colors. like this:</p>
  
  <pre><code>    Image&lt;Gray, Byte&gt; grayscale2 = frame2.Convert&lt;Gray, Byte&gt;();
                  for (int i = 1; i &lt; colors.Length - 1; i++)
                  {
                      var color1 = colors[i].Split('-');
                      var color2 = colors[i+1].Split('-');
                     var img = frame2.InRange(new Bgr(double.Parse(color1[0]), 
                                   double.Parse(color1[1]), double.Parse(color1[2])),
                          new Bgr(double.Parse(color2[0]), double.Parse(color2[1]), 
                                   double.Parse(color2[2]))).Convert&lt;Gray, Byte&gt;();            
                  }
  </code></pre>
  
  <p>"colors" is an array of RGB saved colors as string.
  I am looking for the fastest way to combine (merge) all img in grayscale2.
  Thank you.</p>