title: why is the Haar cascade mouth detection not working?
body: <p>I'm trying to use the haarcascade classifiers the face work just fine but the mouth is not working the multiscale function is not working I've searched the net and tried all solutions that say's the path to the classifier is not right, but still not working. can anyone help me with this </p>
  
  <pre class="lang-py prettyprint-override"><code>import cv2
  
  face_cascade = cv2.CascadeClassifier(
      r"C:\Users\hp\PycharmProjects\haarcascade_frontalface_default.xml")
  mouthCascade = cv2.CascadeClassifier(
      r"C:\Program Files\opencv-master\data\mouth.xml")
  # Read the image
  image = cv2.imread(
      r"C:\Users\hp\Desktop\lip reading dataset\faces\face_18.jpg")
  gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
  cv2.imshow('img', gray)
  cv2.waitKey()
  faces = face_cascade.detectMultiScale(gray, 1.1, 4)
  # Draw a rectangle around the faces
  for (x, y, w, h) in faces:
      cv2.rectangle(image, (x, y), (x + w, y + h), (255, 0, 0), 2)
      roi_color = image[y:y + h, x:x + w]
      roi_gray = gray[y:y + h, x:x + w]
      cv2.imshow('gray', roi_gray)
      cv2.waitKey()
      mouth = mouthCascade.detectMultiScale(roi_gray)
      for (ex, ey, ew, eh) in mouth:
          cv2.rectangle(roi_color, (ex, ey), (ex + ew, ey + eh), (0, 255, 0), 2)
  
  cv2.imshow("Mouth found", image)
  cv2.waitKey(0)
  </code></pre>