def images_rescale(arFrames):
    """
    Rescale array of images (rgb 0-255) to [-1.0, 1.0]
    :param arFrames: Array of frames.
    :return: Array of rescaled frames.
    """

    ar_fFrames = arFrames / 127.5
    ar_fFrames -= 1.

    return ar_fFrames