总是得到这个错误（需要以下参数：-i / - image）

Question

from __future__ import print_function
from skimage.feature import peak_local_max
from skimage.morphology import watershed
from scipy import ndimage
import argparse
import cv2

构造参数解析并解析参数，并且alaways具有相同的错误

ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True,
help="path to input image")
args = vars(ap.parse_args())

image = cv2.imread(args["C:/Users/Wael/Desktop/coins.jpg"])
shifted = cv2.pyrMeanShiftFiltering(image, 21, 51)
cv2.imshow("Input", image)