facedetection with opencv and python only detect eye region

Question

I wrote the script by looking at this website and it works perfectly but the only problem when I run it on my computer is it only detects the eye region. https://pythonprogramming.net/haar-cascade-face-eye-detection-python-opencv-tutorial/

Below is the script I wrote based on the website.

import numpy as np
import cv2

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

image = cv2.imread('frame119.jpg')  
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)

for (x,y,w,h) in faces:
    cv2.rectangle(image,(x,y),(x+w,y+h),(255,0,0),2)
    roi_gray = gray[y:y+h, x:x+w]
    roi_color = image[y:y+h, x:x+w]

    eyes = eye_cascade.detectMultiScale(roi_gray)
    for (ex,ey,ew,eh) in eyes:
        cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)

cv2.imshow('image', image)
cv2.waitKey(0)
cv2.destroyAllWindows()

do I need to add an additional line to fix the problem? Also, the image is in 680x480 dimension, I think that maybe one of the reason why it only detects eye region of the image but I do not have any idea regarding that.

Thank you for the help.

Answer 1

It is not possible to detect eyes if no face is detected .

so try these modification

import numpy as np
import cv2

face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')

image = cv2.imread('frame119.jpg')  
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)

print len(faces)   # it will print no of faces detected 
for (x,y,w,h) in faces:
    cv2.rectangle(image,(x,y),(x+w,y+h),(255,0,0),2)
    roi_gray = gray[y:y+h, x:x+w]
    roi_color = image[y:y+h, x:x+w]
    cv2.imshow('face',roi_color)  # It will show a cropped face , if face is detected
    cv2.waitKey()    
    eyes = eye_cascade.detectMultiScale(roi_gray)
    for (ex,ey,ew,eh) in eyes:
        cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)

cv2.imshow('image', image)
cv2.waitKey(0)
cv2.destroyAllWindows()