python 全图显示ROI图像标记剪切

# -*- coding: utf-8 -*-
import cv2
# 读取图片
img = 'xx.jpg'#图片地址
img = cv2.imread(img)
cv2.imshow('original', img)
# 选择ROI
roi = cv2.selectROI(windowName="original", img=img, showCrosshair=True, fromCenter=True)
x, y, w, h = roi
print(roi)
# 显示ROI并保存图片
if roi != (0, 0, 0, 0):
    crop = img[y:y+h, x:x+w]
    cv2.namedWindow('crop', cv2.WINDOW_NORMAL)
    #cv2.imshow('image',image)
    cv2.imshow('crop', crop)
    #cv2.namedWindow('crop', 0)
    cv2.imwrite('D:\\1', crop)#图片保存地址
    print('Saved!')
# 退出
cv2.waitKey(0)
cv2.destroyAllWindows()