def draw_caption(image, box, caption):
    """ Draws a caption above the box in an image.

    # Arguments
        image   : The image to draw on.
        box     : A list of 4 elements (x1, y1, x2, y2).
        caption : String containing the text to draw.
    """
    b = np.array(box).astype(int)
    cv2.putText(image, caption, (b[0], b[1] - 10), cv2.FONT_HERSHEY_PLAIN, 1, (0, 0, 0), 2)
    cv2.putText(image, caption, (b[0], b[1] - 10), cv2.FONT_HERSHEY_PLAIN, 1, (255, 255, 255), 1)
 Draws a caption above the box in an image.

    # Arguments
        image   : The image to draw on.
        box     : A list of 4 elements (x1, y1, x2, y2).
        caption : String containing the text to draw.
    
keras_retinanet/utils/visualization.py