title: python+opencv - How to plot hsv range?
body: <p>To extract the color, we have this function</p>
  
  <pre><code># define range of blue color in HSV
  lower_blue = np.array([110,50,50])
  upper_blue = np.array([130,255,255])
  
  # Threshold the HSV image to get only blue colors
  mask = cv2.inRange(hsv, lower_blue, upper_blue)
  </code></pre>
  
  <p>How do we actually visualize the range(lower_blue,upper_blue) I define on hsv space?
  Also How do I actually plot a hsv color,but it is not working...?
  I have this code:</p>
  
  <pre><code>upper = np.array([60, 255, 255])
  upper = cv2.cvtColor(upper, cv2.COLOR_HSV2BGR)
  
  
  upper = totuple(upper/-255)
  print(upper)
  plt.imshow([[upper]])
  </code></pre>