The following program shows how you detect a nose:
import cv2 import numpy as np nose_cascade = cv2.CascadeClassifier('./cascade_files/haarcascade_mcs_nose.xml') if nose_cascade.empty(): raise IOError('Unable to load the nose 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) nose_rects = nose_cascade.detectMultiScale(gray, 1.3, 5) for (x,y,w,h) in nose_rects: cv2.rectangle(frame, (x,y), (x+w,y+h), (0,255,0), 3) break cv2.imshow('Nose Detector', frame) c = cv2.waitKey(1) if c == 27: break cap.release() cv2.destroyAllWindows()