def normalize(image, min_=-1000.0, max_=400.0):
    """
    Set the values to [0~1].

    :param image: image array
    :param min_: bottom
    :param max_: top
    :return: convert ct scan to 0~1
    """
    image = (image - min_) / (max_ - min_)
    image[image > 1] = 1.
    image[image < 0] = 0.

    return image