title: object(car) detection in opencv python
body: <p>I am working on one of my college project i.e object(car) detection in opencv python ,i am using opencv 3 and python 3.4. I have a code for it but when i run the code the output is not displayed. It shows that the code is error free but still unable to get the output. I am new to image processing ,so it will be a great help if someone tries to sort out my problem. The code is given below`</p>
  
  <pre><code>import cv2
  import numpy as np
  import argparse
  ap = argparse.ArgumentParser()
  ap.add_agrument("-v","--video",
  help = "path to the (optional) video file")
  args = vars(ap.parse_agrs())
  camera = cv2.VideoCapture(agrs["video"])
  car_cascade = cv2.CascadeClassifier("cars.xml")
  while true:
  ret,frames = camera.read(),cv2.rectangle()
  gray = cv2.cvtColor(frames, cv2.COLOR_BGR2GRAY)
  cars = car_cascade.detectionMultiScale(gray, 1.1,1)
  for (x,y,w,h) in cars:
  cv2.rectangular()frames,(x,y),(x+w,y+h), (0,0,255),2)
  cv2.imshow ('video',frames)
  cv2.waitkey(0)
  </code></pre>