# http://search.cpan.org/~srezic/Tk-804.033/pod/Image.pod
   # It's necessary to use the "delete" method to delete an image object and
   # free memory associated with it. Just using a lexical variable for storing
   # the image object and letting the variable to go out of scope or setting to
   # undef is not sufficient.
   #
   # $tk_ph_image is a Tk::Photo object
   $tk_ph_image->delete if $tk_ph_image->blank;