OpenCV 3.x with Python By Example - Second Edition

Detecting a mouth

This time, using Haar classifiers, we are going to extract a mouth position from the input video stream, and on the code below this code we are going to use those coordinates to place a mustache on the face:

import cv2 
import numpy as np 
 
mouth_cascade = cv2.CascadeClassifier('./cascade_files/haarcascade_mcs_mouth.xml') 
  if mouth_cascade.empty():   raise IOError('Unable to load the mouth cascade classifier xml file')  cap = cv2.VideoCapture(0) ds_factor = 0.5  while True:     ret, frame = cap.read()     frame = cv2.resize(frame, None, fx=ds_factor, fy=ds_factor, interpolation=cv2.INTER_AREA)     gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)      mouth_rects = mouth_cascade.detectMultiScale(gray, scaleFactor=1.7, minNeighbors=11)  for ...