opencv人脸检测笔记（简版

import cv2
cap = cv2.VideoCapture(0)
while True:
    ret, image = cap.read()
    #导入opencv自带的人脸检测分类器
    faceCascade = cv2.CascadeClassifier(r'E:\conda\envs\py36\Lib\site-packages\cv2\data\haarcascade_frontalface_alt.xml')
    gray = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)
    #检测人脸
    faces = faceCascade.detectMultiScale(gray, scaleFactor = 1.12, minNeighbors = 2, minSize = (5,5))
    print(faces)
    print("发现{0}个人脸!".format(len(faces)))
    # 逐个标注人脸，（我检测时只有一个人）
    if len(faces)==1:
        for(x,y,w,h) in faces:
            cv2.rectangle(image,(x,y),(x+w,y+w),(0,255,0),2)
            # 把红框区域单独显示
            image=image[y:y+w,x:x+w]
            #图片缩放，resize与shape获得的尺寸相反
            image=cv2.resize(image,(640,480))
            cv2.imshow("dect",image)
    else:pass
    if cv2.waitKey(10) & 0xff == 27:
         break