如何在python中使用MTCNN从文件夹中的图像中提取人脸？

from mtcnn import MTCNN
from PIL import Image
import os

detector = MTCNN()

def extract_faces(image_path):
    image = Image.open(image_path)
    image = image.convert('RGB')
    pixels = np.asarray(image)
    results = detector.detect_faces(pixels)
    
    faces = []
    for result in results:
        x, y, width, height = result['box']
        face = pixels[y:y+height, x:x+width]
        face = Image.fromarray(face)
        face = face.resize((160, 160))
        faces.append(face)
    
    return faces

folder_path = 'path/to/folder'
faces = []
for filename in os.listdir(folder_path):
    if filename.endswith('.jpg') or filename.endswith('.png'):
        image_path = os.path.join(folder_path, filename)
        extracted_faces = extract_faces(image_path)
        faces.extend(extracted_faces)