如何高效地将数千张高清照片加载到pandas df中并转换为HDF？

import os
from PIL import Image
import numpy as np
import pandas as pd

def process_image(image_path):
    # 读取和处理图像
    image = Image.open(image_path)
    image = image.resize((256, 256))  # 缩放图像到指定大小
    image = np.array(image)  # 转换为numpy数组
    return image

def load_images_to_dataframe(image_folder):
    # 遍历图像文件夹中的所有文件
    image_files = os.listdir(image_folder)
    df = pd.DataFrame(columns=['image_data'])  # 创建空的DataFrame

    for image_file in image_files:
        image_path = os.path.join(image_folder, image_file)
        image_data = process_image(image_path)
        df = df.append({'image_data': image_data}, ignore_index=True)

    return df

image_folder = 'path/to/folder'  # 图像文件夹路径
df = load_images_to_dataframe(image_folder)

df.to_hdf('output.h5', key='data', mode='w')  # 保存为HDF文件