python调用摄像头拍照并保存

import cv2
import os
#引入库
 
print("=============================================")
print("=  热键(请在摄像头的窗口使用)：             =")
print("=  z: 更改存储目录                          =")
print("=  x: 拍摄图片                              =")
print("=  q: 退出                                  =")
print("=============================================")
#提醒用户操作字典
 
class_name = input("请输入存储目录（python安装目录下才行，如：d:\python\py_image)：")
while os.path.exists(class_name):
    class_name = input("目录已存在！请输入存储目录：")
os.mkdir(class_name)
#存储
 
index = 1
cap = cv2.VideoCapture(0 + cv2.CAP_DSHOW)
width = 640
height = 480
w = 360
cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)
crop_w_start = (width-w)//2
crop_h_start = (height-w)//2
print(width, height)
#设置特定值
 
while True:
    ret, frame = cap.read()
   
    frame = frame[crop_h_start:crop_h_start+w, crop_w_start:crop_w_start+w]
    #没理解？
 
    frame = cv2.flip(frame,1,dst=None)
    #镜像显示
    cv2.imshow("capture", frame)
    #显示
 
    input = cv2.waitKey(1) & 0xFF
    if input == ord('z'):
        class_name = input("请输入存储目录：")
        while os.path.exists(class_name):
            class_name = input("目录已存在！请输入存储目录：")
        os.mkdir(class_name)
    #存储
 
    elif input == ord('x'):
        cv2.imwrite("%s/%d.jpeg" % (class_name, index),
                    cv2.resize(frame, (224, 224), interpolation=cv2.INTER_AREA))
        print("%s: %d 张图片" % (class_name, index))
        index += 1
    #？
    if input == ord('q'):
        break
    #退出
        
cap.release()
cv2.destroyAllWindows()
    #关闭窗口