将 IP 网络摄像头与 OpenCV 运动跟踪结合使用

Question

I'm trying to make a tracking laser webcam toy for my cat, but I am currently struggling with the IP webcam from an Android phone as it won't display anything and i get an error "initStream Failed to reset streams" I have attached the code below! I'm still new to Python and would love to learn more! =)

import cv2
import numpy as np
#Cam
url = "http://192.168.x.x:8080/shot.jpg"
img_resp = requests.get(url)
img_arr = np.array(bytearray(img_resp.content),dtype=np.uint8)
img = cv2.imdecode(img_arr,-1)
cap =cv2.VideoCapture(0)
ret, frame = cap.read()
#Movement tracker
while cap.isOpened():
    ret = cap.set(3,320)
    ret = cap.set(4,240)
    diff = cv2.absdiff(frame, frame)
    gray = cv2.cvtColor(diff, cv2.COLOR_BGR2GRAY)
    blur = cv2.GaussianBlur(gray, (5,5), 0)
    _, thresh = cv2.threshold(blur, 20, 255, cv2.THRESH_BINARY)
    dilated = cv2.dilate(thresh, None, iterations=3)
    contours, _ = cv2.findContours(dilated, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

    for contour in contours:
        (x, y, w, h) = cv2.boundingRect(contour)
        if cv2.contourArea(contour) < 900:
            continue
        cv2.rectangle(frame, (x, y), (x+w, y+h), (255, 20, 30), 3)
        cv2.putText(frame, "Status: {}".format('Movement'), (10, 20), cv2.FONT_HERSHEY_SIMPLEX,
                    1, (0, 0, 255), 3)
        cv2.circle(frame, (x, y), 3, (200, 50, 180), 2)

        image = cv2.resize(frame, (1280, 720))
        cv2.imshow("feed", frame)
        ret, frame2 = img.read()

        if cv2.waitKey(1) == 27:
            break
        cv2.destroyAllWindows()
        img.release()

Answer 1

I use IP Webcam application on my android phone. Just need to define url variable as below:

url = 'http://your IP address:port number/video' # e.g. url = 'http://192.168.43.1:8080/video'

You will see IP address and port number on the mobile phone screen when the app is running. And after that you need to pass url as an argument to cv2.VideoCapture() method like this cap = cv2.VideoCapture(url) instead of cap = cv2.VideoCapture(0) . It works fine for me. No need to say that PC and mobile phone are connected via Wi-Fi network (or mobile hotspot).