Resize and pad images

resize.py

import os
import cv2

dir_files = os.listdir('raw_data')

extensions = [filename[-4:] for filename in dir_files]
for ext in extensions:
    assert ext == '.jpg'

max_width = 0
max_heigth = 0
for filename in dir_files:
    img = cv2.imread('raw_data/' + filename, cv2.IMREAD_COLOR)
    height, width = img.shape[:2]
    if height > max_heigth:
        max_heigth = height
    if width > max_width:
        max_width = width

for filename in dir_files:
    img = cv2.imread('raw_data/' + filename, cv2.IMREAD_COLOR)
    height, width = img.shape[:2]
    h_diff = max_heigth - height
    w_diff = max_width - width
    t, b, l, r = (0, 0, 0, 0)
    if h_diff > 0:
        if h_diff % 2 == 0:
            t = int(h_diff / 2)
            b = int(h_diff / 2)
        elif h_diff % 2 == 1:
            t = int(h_diff / 2)
            b = int(h_diff / 2) + 1
        else:
            raise Exception("impossible")
    if w_diff > 0:
        if w_diff % 2 == 0:
            l = int(w_diff / 2)
            r = int(w_diff / 2)
        elif w_diff % 2 == 1:
            l = int(w_diff / 2)
            r = int(w_diff / 2) + 1
        else:
            raise Exception("impossible")

    pad_img = cv2.copyMakeBorder(img, t, b, l, r, borderType=cv2.BORDER_REFLECT_101)
    cv2.imwrite('output/'+str(filename), pad_img)