def build_lut(f, dtype=int):
    """
    Method to load a remap file into a lut

    Parameters
    ----------
    f : str
        file name
    dtype : type
        int or float type, defaults to int

    Returns
    -------
        dict
    """
    d = {}
    with open(f) as foo:
        for line in foo:
            temp = line.strip().split("#")[0]
            if not temp:
                continue
            else:
                l = temp.split(":")
                d[dtype(l[0])] = float(l[1])
    return d