如何在Python中使用OpenCV泛化轮廓手写字符？

import cv2
import numpy as np

image = cv2.imread('handwritten.jpg')
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

ret, thresh = cv2.threshold(gray, 127, 255, cv2.THRESH_BINARY_INV)
kernel = np.ones((5,5), np.uint8)
dilation = cv2.dilate(thresh, kernel, iterations=1)

contours, hierarchy = cv2.findContours(dilation, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

for contour in contours:
    epsilon = 0.01 * cv2.arcLength(contour, True)
    approx = cv2.approxPolyDP(contour, epsilon, True)

cv2.drawContours(image, [approx], 0, (0, 255, 0), 2)

cv2.imshow('Result', image)
cv2.waitKey(0)
cv2.destroyAllWindows()