docs: def checkArgs(args):
      """Checks the arguments and options.
  
      :param args: an object containing the options of the program.
  
      :type args: argparse.Namespace
  
      :returns: ``True`` if everything was OK.
  
      If there is a problem with an option, an exception is raised using the
      :py:class:`ProgramError` class, a message is printed to the
      :class:`sys.stderr` and the program exists with code 1.
  
      """
      # Checking the input file
      if not os.path.isfile(args.problematic_samples):
          msg = "{}: no such file".format(args.problematic_samples)
          raise ProgramError(msg)
  
      # Checking the raw directory
      if not os.path.isdir(args.raw_dir):
          msg = "{}: no such directory".format(args.raw_dir)
          raise ProgramError(msg)
  
      # Checking the DPI value
      if args.dpi < 10:
          msg = "{}: DPI too low".format(args.dpi)
          raise ProgramError(msg)
  
      return True