程式碼：

import cv2
import os
import dlib
'''
用dlib 識別 用opencv把手機拍的照片大小縮放 不是就不變  識別是否是圖片格式 不是跳過
'''
# 讀取函式，用來讀取資料夾中的所有函式，輸入引數是檔名
def read_directory(directory_name):
    for filename in os.listdir(directory_name):
        a= filename.split(".")[-1]
        if str(a) in ["JPG",'PNG','jpg','png']:
            
 
# 用matplotlib的路徑
            img1 = directory_name + "\\" + filename
            img3 = cv2.imread(img1)
            img2 = cv2.imread(img1)
            if img3.shape[0] >= int(2000): #現在手機畫素高了 識別不了 還是圖片縮小識別
                scale_percent = 25  # percent of original size   縮小到原來25%
                width = int(img3.shape[1] * scale_percent / 100)
                height 
 
= int(img3.shape[0] * scale_percent / 100)
                dim = (width, height)
                img = cv2.resize(img3, dim, interpolation=cv2.INTER_AREA)
            else:
                img = img3
            gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
            # 人臉分類器
            detector = dlib.get_frontal_face_detector()
            
 
# 獲取人臉檢測器
            predictor = dlib.shape_predictor(
                "shape_predictor_68_face_landmarks.dat"
            )
            dets = detector(gray, 1)
            if len(dets):  # 不為0則檢測到人臉
                for face in dets:
                    shape = predictor(img, face)  # 尋找人臉的68個標定點
                    # 遍歷所有點，打印出其座標，並圈出來
                    for pt in shape.parts():
                        pt_pos = (pt.x, pt.y)
                        cv2.circle(img, pt_pos, 1, (0, 255, 0), 1)
                    b = filename.split(".")[-2]
                    cv2.imwrite(r"H:\renwu__opencv\%s.%s" % (b, a), img2)
                    # print(filename)
                    cv2.destroyAllWindows()
            else:
                print('沒找到人臉！')
        else:
            print('跳過！')
read_directory(r'H:\renwu__opencv\zhaopian')#這裡傳入所要讀取資料夾的絕對路徑，加引號（引號不能省略！） 不要有中文