def pdf2png(file_in, file_out):
command = '<STR_LIT>'.format(file_in, file_out)<EOL>_subprocess.call(_shlex.split(command))<EOL>
Uses `ImageMagick <http://www.imagemagick.org/>`_ to convert an input *file_in* pdf to a *file_out* png. (Untested with other formats.)

Parameters
----------

file_in : str
    The path to the pdf file to be converted.
file_out : str
    The path to the png file to be written.