StreamingHttpResponse don't redirect and thread is freezing

Django Internals Async
1

Hi, I’m using Django 5.0, and I wrote the following code to get the facial recognition from the device camera and compare it with the stored image. This part behaves well, but the code never performs the redirect and freezes. Please how could I improve my code and fix this problem?

import os
import cv2
import threading
import face_recognition
from queue import Queue

from django.shortcuts import render, redirect
from django.http import StreamingHttpResponse
from django.views.decorators import gzip

from .forms import FormKYC
from .models import KYCData

def user_profile(request, pk):
    kyc = KYCData.objects.get(id=pk)
    context = {
        'kyc': kyc
    }
    return render(request, 'kycapp/user_profile.html', context=context)
@gzip.gzip_page
def camera_view(request, pk):
    try:
        cam = VideoCamera()
        response = StreamingHttpResponse(gen(cam, pk), content_type="multipart/x-mixed-replace;boundary=frame")
        return response
    except:
        pass
    return render(request, 'kycapp/camera.html')

class VideoCamera(object):
    def __init__(self):
        self.video = cv2.VideoCapture(0)
        (self.grabbed, self.frame) = self.video.read()
        self.queue = Queue()  # Queue to communicate between threads
        self.thread = threading.Thread(target=self.update, args=())
        self.thread.daemon = True
        self.thread.start()

    def stop(self):
        self.video.release()
        self.queue.put(None)  
        self.thread.join()
    def get_frame(self):
        image = self.frame
        _, jpeg = cv2.imencode('.jpg', image)
        return jpeg.tobytes()

    def update(self):
        while True:
            if not self.thread.is_alive():  # Break the loop if the thread is not alive
                break
            (self.grabbed, self.frame) = self.video.read()

base_path = "[path_of]"

def gen(camera, pk):
    face_cascade = cv2.CascadeClassifier(base_path)

    kyc_data = KYCData.objects.get(id=pk)
    image_doc = kyc_data.images.document_image.file

    reference_image = cv2.imread(str(image_doc))
    reference_face_encoding = face_recognition.face_encodings(reference_image)[0]

    match_found = False

    while match_found == False:
        frame = camera.get_frame()
        gray = cv2.cvtColor(camera.frame, cv2.COLOR_BGR2GRAY)
        faces = face_cascade.detectMultiScale(gray, scaleFactor=1.3, minNeighbors=5)
        for (x, y, w, h) in faces:
            cv2.rectangle(camera.frame, (x, y), (x + w, y + h), (255, 0, 0), 2)

        face_encodings = face_recognition.face_encodings(camera.frame)
        if len(face_encodings) > 0:
            for face_encoding in face_encodings:
                match = face_recognition.compare_faces([reference_face_encoding], face_encoding)

                if match[0]:
                    kyc_data.camera_validation = True
                    kyc_data.save()
                    match_found = True
                    camera.stop()

        yield (b'--frame\r\n'
               b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')

    return redirect('profile', pk=pk)
2

Do not create threads within your Django process.

If you’ve got a long running task that needs to be run independently and outside the context of the request / response cycle of a view, use something like Celery or Channels to manage that kind of work.

Also, I’m curious - how are you expecting this to work through a browser, when Django is running on the server? Do you actually have this running on a server yet, or are you just testing this using runserver on your development machine?