text: ######################################################################
  # Author: Dr. Jan Pearce      TODO: Change this to your name(s)
  # Username: pearcej           TODO: Change this to your username(s)
  #
  # Assignment: A09: PPM Steganography
  #
  # Note: This assignment may be completed alone or in a pair or programmers, but not more than 2.
  # If you work in a pair, both partners must make committs to the repo
  #
  # Purposes:
  # - deepen comfort in use of classes
  # - use triply nested lists, considering memory management issues of shallow copy vs. deep copy
  # - design algorithms for encryption/decryption and compute Big-O for each
  # ######################################################################
  # Acknowledgements:
  #
  # Original code written by Dr. Jan Pearce with modifications by Dr. Scott Heggen and additional
  # modificatitons by Dr. Jan Pearce
  #
  # Ben Stephenson: http://pages.cpsc.ucalgary.ca/~jacobs/Courses/cpsc217/W10/code/Topic7/ppm.py
  # working from a class: http://bytes.com/topic/python/answers/520360-trouble-displaying-image-tkinter
  #
  # licensed under a Creative Commons
  # Attribution-Noncommercial-Share Alike 3.0 United States License.
  ####################################################################################
  
  from ppm import *
  # HINT: Be sure you work with a single ppm object at a time
  
  
  def main():
      # The following interaction is just for testing.  You will improve this.
  
      wn = PPM_set_up()   # To use the PPM class, this must appear at the beginning of your program. You'll pass wn into
                          # the class init method when creating new PPM objects
  
      print("\nWelcome to the PPM introduction!\n")
  
      # Example using the default file
      ppmdefault = PPM(wn)
      ppmdefault.PPM_display()            # NOTE: This displays the image, but it's really small! It may be hard to find.
      print("---")
  
      # Example using a user-defined file
      filename = input("Please input name of PPM-P3 file: ")
      ppmobject = PPM(wn, filename)
      ppmobject.PPM_display()
  
  
      # TODO Add your own method calls for the methods you are completing/creating from scratch
  
  
      print("\nPush the Quit button to exit all files.")
  
      PPM_render(wn) # needed to render all of the images you have instantiated
      pass
  
  main()
  