如何在python中获得平面布置图的外轮廓？

import cv2
import numpy as np

image = cv2.imread('path_to_image.jpg')

gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (5, 5), 0)
_, thresh = cv2.threshold(blur, 127, 255, cv2.THRESH_BINARY_INV)

contours, _ = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

outer_contour = max(contours, key=cv2.contourArea)

contour_image = np.zeros_like(image)
cv2.drawContours(contour_image, [outer_contour], -1, (0, 255, 0), 2)

cv2.imshow('Contour Image', contour_image)
cv2.waitKey(0)
cv2.destroyAllWindows()