调用本地电脑摄像头并进行按P进行捕获照片并保存，按下Q退出

灰度摄像头显示：

import cv2
cap = cv2.VideoCapture(0)
if not cap.isOpened():print("Cannot open camera")exit()
while True:# 逐帧捕获ret, frame = cap.read()# 如果正确读取帧，ret为Trueif not ret:print("Can't receive frame (stream end?). Exiting ...")break# 我们在框架上的操作到这里gray = cv2.cvtColor(frame, cv2.COLOR_GRAY2BGR)#这里的cv2.COLOR_BGR2GRAY为灰度图，当然也可以选择彩色图# 显示结果帧ecv2.imshow('frame', gray)if cv2.waitKey(1) == ord('q'):break
# 完成所有操作后，释放捕获器
cap.release()
cv2.destroyAllWindows()

参考OpenCV手册：http://woshicver.com/ThirdSection/2_2_%E8%A7%86%E9%A2%91%E5%85%A5%E9%97%A8/

调用摄像头p拍照，q退出

import cv2cap = cv2.VideoCapture(0)
index = 0
while True:ret,frame = cap.read()# Our operations on the frame come heregray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)# Display the resulting framecv2.imshow('frame',gray)if cv2.waitKey(1) & 0xFF == ord('p'):cv2.imwrite("beyond.jpg",frame)index = index + 1if cv2.waitKey(1) & 0xFF == ord('q'):break# When everything done, release the capture
cap.release()
cv2.destroyAllWindows() 

参考：https://www.jb51.net/article/165125.htm