• This code is very simple and fast. you just need to add the path of your folder of images and then give the size of the output images!

import PIL
import os
import os.path
from PIL import Image

f = r'Address of input folder of images' # for example C:/Myimages
for file in os.listdir(f):
    f_img = f+"/"+file
    img = Image.open(f_img)
    img = img.resize((48,48))  $ the needed size of images. here we needed 48*48
    img.save(f_img)