DBG: Create fully functional shell code to read and write
COD: Include registration and initial set up parameters
COD: Finish registration code, display results and write out result
DBG: Fix errors in code
DBG-BNF: Cast images and attempt to fix "FixedImageRegion is empty" error

Attempted to run code with .png images and error occured. Changes are
to cast input images and output images to fix error. BUG NOT FIXED