def crop_image(img, crop_constant=2):
    """Crop image in slightly, helps with splitting artifacts. 

    :param numpy.ndarray img: the image to be framed.
    :param int crop_constant: number of pixels to eat in.

    :return numpy.ndarray img: cropped img.
    """
    rows = len(img)
    cols = len(img[0])
    img = img[crop_constant:rows - crop_constant, crop_constant:cols -
        crop_constant]
    return img
