def _to_pydim(key: str) -> str:
    """Convert ImageJ dimension convention to Python/NumPy."""
    pydims = {
        "Time": "t",
        "slice": "pln",
        "Z": "pln",
        "Y": "row",
        "X": "col",
        "Channel": "ch",
    }

    if key in pydims:
        return pydims[key]
    else:
        return key