多张人脸识别

import cv2 as cv
def face_detect_demo():
    # 将图片转化为灰度图片
    gray = cv.cvtColor(img,cv.COLOR_BGR2GRAY)
    # 加载特征数据
    face_detector = cv.CascadeClassifier('D:/Opencv/opencv/sources/data/haarcascades/haarcascade_frontalface_default.xml')
    faces = face_detector.detectMultiScale(gray,scaleFactor=1.01,minNeighbors=4,maxSize=(30,30))
    for x,y,w,h in faces:
        print(x,y,w,h)
        cv.rectangle(img,(x,y),(x+w,y+h),color=(0,255,0),thickness=2)
        cv.circle(img,center=(x+w//2,y+h//2),radius=w//2,color=(0,0,255),thickness=2)
    cv.imshow('result',img)
# 加载图片
img = cv.imread('C:/Users/87823/Desktop/NBA2.jfif')
face_detect_demo()
cv.waitKey(0)
cv.destroyAllWindows()