Steps
1. Your output image file should be a single PPM on the syslab filesystem.
2. Convert this file to PNG using the command: convert out.ppm out.png
3. Make a copy of this PNG-file named yourusername.png for whatever your username is.
4. Put this file in ~smtorbert/turnin using either...
      cp yourusername.png ~smtorbert/turnin
            -or-
      mv yourusername.png ~smtorbert/turnin