opencv人脸检测

找了一张自己喜欢的《超人前传》剧照

其中的xml分类器需要到https://github.com/opencv/opencv/tree/master/data/haarcascades去下载

import numpy as np
import cv2

face_cascade = cv2.CascadeClassifier("data/haarcascade_frontalface_default.xml")
eye_cascade = cv2.CascadeClassifier("data/haarcascade_eye.xml")
img = cv2.imread("img/test1.jpg")
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
for (x, y, w, h) in faces:
    img = cv2.rectangle(img, (x, y), (x + w, y + h), (255, 0, 0), 2)
    roi_gray = gray[y : y + h, x : x + w]
    roi_color = img[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.namedWindow("img", 0)
cv2.resizeWindow("img", 800, 600)
cv2.imshow("img", img)
cv2.waitKey(0)
cv2.destroyAllWindows()