title: Creating a mask based on a colour range
body: <p>I'm trying to wind turbines in pictures. To make this easier I try to remove the background based on the color (sky is blue, ground is green) just something basic. But it seems that my mask is always completely black. What am i doing wrong?</p>
  <p>kind regards</p>
  <pre><code>Mat HSV, mask, outputHSV;
      // Convert from BGR to HSV colorspace
      cv::cvtColor(frame,HSV, COLOR_BGR2HSV);
  
      int low_H = 220, low_S = 60, low_V = 90;
      int high_H = 240, high_S = 100, high_V = 100;
  
      // Detect the object based on HSV Range Values
      inRange(HSV, Scalar(low_H, low_S, low_V), Scalar(high_H, high_S, high_V), mask);
  
      // creating an inverted mask to segment out the cloth from the frame
      bitwise_and(frame,HSV,outputHSV,mask = mask);
      cv::imshow(&quot;HSV_filter&quot;, outputHSV);
  </code></pre>