title: Overlaying a box on label image using Tkinter
body: <p>I am using Tkinter and the <code>grid()</code> layout manager to create a GUI.  I am showing the image in my GUI using a label, on a tabbed window:</p>
  <pre><code>label2 = ttk.Label(tab2)
  image2 = PhotoImage(file=&quot;lizard.gif&quot;)
  label2['image'] = image2
  label2.grid(column=0, row=0, columnspan=3)
  </code></pre>
  <p>For illustration, let's say the image is 300 x 900.  If I know a set of coordinates within the image, how can I overlay a shaded box on the image, defined by the known (A,B,C,D which are shown just for the illustration purpose) coordinates?</p>
  <p><a href="https://i.stack.imgur.com/A0Znz.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/A0Znz.jpg" alt="Illustration of concept" /></a></p>