def log(img):
    """
        Element-wise natural log of an `Image`.

        If the `Image` is empty, returns the empty `Image`.

        Example
        -------
        >>> import descarteslabs.workflows as wf
        >>> img = wf.Image.from_id("landsat:LC08:PRE:TOAR:meta_LC80270312016188_v1").pick_bands("red")
        >>> img.log().compute(geoctx) # doctest: +SKIP
        ImageResult:
        ...
        """
    from ..math import arithmetic
    return arithmetic.log(img)
