day4 边缘检测Canny

# coding=utf-8

import cv2
import numpy as np

filename = ‘woman.JPEG‘

#读入图像，以灰度格式
img = cv2.imread(filename)
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

canny1 = cv2.Canny(img,200,300)
                  #200：最小阈值   300：最大阈值
                  #灰度梯度高于maxVal被认为是边界
                  #低于minVal抛弃

cv2.imshow("canny",canny1)
cv2.waitKey()
cv2.destroyAllWindows()