def lpph2lpmm(lpph, n, pixelPitch):
    """Convert resolution specified in Line-Pair per Picture Height (LPPH)
    to Line-Pair per Milli Meters (LPMM)

    Parameters
    ----------
    lpph : float
        resolution in terms of Line-Pair per Picture Height (LPPH)
    n : integer
        Number of pixels in the picture along the dimension
        (height or width) of consideration
    pixelPitch : float
        pixel pitch of the sensor in microns

    Returns
    -------
    lpmm : float
        resolution in terms of Line-Pair per Milli-Meters (LPMM)
    """
    return lpph*1000.0/(n*pixelPitch)