烧瓶和openCV多次POST请求

Question

所以我正在制作一个Flask应用程序，它可以打开和关闭树莓派中的相机。服务器代码如图所示：

from flask import Flask, request, Response
import requests, json, ast
import cv2, time, pandas
import threading
# importing datetime class from datetime library 
from datetime import datetime

app = Flask(__name__)
@app.route('/', methods=['POST'])
def camera():
from camera_opencv_class import videoCapture
data=list(request.form.keys())[0]
print(data)
if data=="turnon":
video_object=videoCapture()
t_videoCapture=threading.Thread(target=video_object.show)
t_videoCapture.start()
for i in threading.enumerate():
i.record=True
return Response(status=200)
elif data=="turnoff":
for i in threading.enumerate():
i.record=False
return Response(status=200)
return Response(status=200)
if __name__ == '__main__':
app.run(host= '0.0.0.0',debug=True,port=8000)

并显示camera_opencv_class代码：

import cv2
from datetime import datetime
import threading
class videoCapture:
# Capturing video 
def show(placeholder):
video = cv2.VideoCapture(0)
# Assigning our static_back to None 
static_back = None

# List when any moving object appear 
motion_list = [ None, None ] 

videoCapture_thread=threading.currentThread()
while getattr(videoCapture_thread,"record",True):
# Reading frame(image) from video 
check, frame = video.read() 

# Initializing motion = 0(no motion) 
motion = 0

gray=cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)

gray=cv2.GaussianBlur(gray,(21,21),0)

if static_back is None:
static_back=gray
continue

diff_frame=cv2.absdiff(static_back,gray)

thresh_frame=cv2.threshold(diff_frame,30,255,cv2.THRESH_BINARY)[1]
thresh_frame=cv2.dilate(thresh_frame,None,iterations=2)

(cnts,_)=cv2.findContours(thresh_frame.copy(),cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

for contour in cnts:
if cv2.contourArea(contour)<10000:
continue
motion=1
(x,y,w,h)=cv2.boundingRect(contour)
cv2.rectangle(frame,(x,y),(x+w,y+h),(0,255,0),3)

#  Displaying image in gray_scale 
#cv2.imshow("Gray Frame", gray) 

# Displaying the difference in currentframe to 
# the staticframe(very first_frame) 
#cv2.imshow("Difference Frame", diff_frame) 

# Displaying the black and white image in which if 
# intencity difference greater than 30 it will appear white 
#cv2.imshow("Threshold Frame", thresh_frame) 

# Displaying color frame with contour of motion of object 
cv2.imshow("Color Frame", frame) 

key = cv2.waitKey(1)
#print("on")  

video.release() 

# Destroying all the windows 
cv2.destroyAllWindows() 

正如你所看到的，当我发送打开相机的请求时，线程将开始打开相机，而当我发送关闭相机的请求后，线程的"；记录"；属性将为False，因此线程将结束。这是有效的。然而，当我再次发送开机请求时，创建了一个新线程，但什么也没发生；相机没有打开。有人知道为什么吗？也许是openCV中的一些独特之处不允许我这样做？或者有人知道更好的方法来完成这项任务吗？服务器是使用Ngrok转发的，我使用一台单独的计算机进行请求(主要目标是使用我手机上的IFTTT(

Answer 1

添加

t_video_capture.join()

然后返回响应。