python opencv捕获摄像头并显示内容的实现

import cv2
import numpy as np
import pickle
import matplotlib.pyplot as plt
 
cap = cv2.VideoCapture(0)
 
while True:
  ret,frame = cap.read()
  # Our operations on the frame come here
  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  # Display the resulting frame
  cv2.imshow('frame',gray)
  if cv2.waitKey(1) & 0xFF == ord('q'):
    break
 
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows() 

import cv2
import numpy as np
import pickle
import matplotlib.pyplot as plt
 
cap = cv2.VideoCapture(0)
index = 0
while True:
  ret,frame = cap.read()
  # Our operations on the frame come here
  gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  # Display the resulting frame
  cv2.imshow('frame',gray)
  if cv2.waitKey(1) & 0xFF == ord('p'):
    cv2.imwrite("kk.jpg",frame)
    index = index + 1
  if cv2.waitKey(1) & 0xFF == ord('q'):
    break
 
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows() 

import cv2

# 获取本地摄像头
# folder_path 截取图片的存储目录
def get_img_from_camera_local(folder_path):
  cap = cv2.VideoCapture(0)
  i = 1
  while True:
    ret, frame = cap.read()
    cv2.imshow("capture", frame)
    print str(i)
    cv2.imwrite(folder_path + str(i) + '.jpg', frame) # 存储为图像
    if cv2.waitKey(1) & 0xFF == ord('q'):
      break
    i += 1
  cap.release()
  cv2.destroyAllWindows()

# 获取网络摄像头，格式：rtsp://username:pwd@ip/
# folder_path 截取图片的存储目录
def get_img_from_camera_net(folder_path):
  cap = cv2.VideoCapture('rtsp://username:pwd@ip/')
  i = 1
  while True:
    ret, frame = cap.read()
    cv2.imshow("capture", frame)
    print str(i)
    cv2.imwrite(folder_path + str(i) + '.jpg', frame) # 存储为图像
    if cv2.waitKey(1) & 0xFF == ord('q'):
      break
    i += 1
  cap.release()
  cv2.destroyAllWindows()

# 测试
if __name__ == '__main__':
  folder_path = 'D:\\img_from_camera\\'
  get_img_from_camera_local(folder_path)