main.py

import cv2

def Camera():
    cam = cv2.VideoCapture(1) # To Capture Webcam 

    cam.set(3, 740)
    cam.set(4, 580)

    classNames = []
    classFile = 'coco.names'

    with open(classFile, 'rt') as f:
        classNames = f.read().rstrip('\n').split('\n')

    configPath = 'ssd_mobilenet_v3_large_coco_2020_01_14.pbtxt'
    weightpath = 'frozen_inference_graph.pb'

    net = cv2.dnn_DetectionModel(weightpath, configPath)
    net.setInputSize(320 , 230)
    net.setInputScale(1.0 / 127.5)
    net.setInputMean((127.5, 127.5, 127.5))
    net.setInputSwapRB(True)

    # Define the codec and create VideoWriter object
    fourcc = cv2.VideoWriter_fourcc(*'XVID')
    out = cv2.VideoWriter('output.avi', fourcc, 20.0, (640, 480))

    while True:
        success, img = cam.read()
        classIds, confs, bbox = net.detect(img, confThreshold=0.5)

        if len(classIds) != 0:
            for classId, confidence, box in zip(classIds.flatten(), confs.flatten(), bbox):
                cv2.rectangle(img, box, color=(0, 255, 0), thickness=2)
                cv2.putText(img, classNames[classId-1], (box[0] + 10, box[1] + 20), 
                            cv2.FONT_HERSHEY_COMPLEX, 1, (0, 255, 0), thickness=2)

        # Write the frame into the file 'output.avi'
        out.write(img)

        cv2.imshow('Output', img)
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

    # Release everything if job is finished
    cam.release()
    out.release()
    cv2.destroyAllWindows()

Camera()