title: Python Pillow's ImageTk does not display images originating from certain file types
body: <p>Suppose I have the following code: </p>
  
  <pre><code>from PIL import Image, ImageTk
  from tkinter import *
  
  im = Image.open(&lt;Some file path&gt;)
  root = Tk()
  photo = ImageTk.PhotoImage(im)
  label = Label(root, image=photo)
  label.pack()
  root.mainloop()
  </code></pre>
  
  <p>When the file path is a typical file type like a png, the program will display the image as you would expect it to. However, when I give it a tga file (uncompressed Targa32 128x128), it does not show the image (just leaves a blank area). However, the image does show when using Pillow's Image.show() method, just not with tkinter. </p>
  
  <p>Note that I'm only working with global variables so it can't be a garbage collection issue. </p>
  
  <p>How can I get my tga files to show up in my tkinter interface?</p>