TensorFlow图片转为数据

把文件夹中的图片文件，转换为数组

import os
from PIL import Image
import numpy as np

def load_data():
    data = np.empty((42000,1,28,28),dtype="float32")
    label = np.empty((42000,),dtype="unit8")

    imgs = os.listdir("F:\elc\TensorFlow\data\mnist")
    num = len(imgs)
    for i in range(num):
        img = Image.open("F:\elc\TensorFlow\data\mnist" + imgs[i])
        arr = np.asarray(img,dtype="float32")
        data[i,:,:,:] = arr
        label[i] = int(imgs[i].split('.')[0])

        return data,label