Does Tesseract have textonly_pdf capability?

    Available in v4.00.00alpha since January 2017. Best to
    parse the parameter list

def has_textonly_pdf():
    """Does Tesseract have textonly_pdf capability?

    Available in v4.00.00alpha since January 2017. Best to
    parse the parameter list
    """
    args_tess = ['tesseract', '--print-parameters', 'pdf']
    params = ''
    try:
        params = check_output(args_tess, universal_newlines=True, stderr=STDOUT)
    except CalledProcessError as e:
        print("Could not --print-parameters from tesseract", file=sys.stderr)
        raise MissingDependencyError from e
    if 'textonly_pdf' in params:
        return True
    return False