HYTOS

import numpy as np

import cv2, os

rootPath = 'X:\CPChem\drawings'

imgList = os.listdir(rootPath)

startX, startY, endX, endY = [417, 3727, 7723], \

                             [5815, 5534, 5262], \

                             [9374, 9374, 9374], \

                             [6096, 6096, 6096]

print('start')

for imgPath in imgList:

    fullPath = os.path.join(rootPath, imgPath)

    img = cv2.imread(fullPath, cv2.IMREAD_GRAYSCALE)

    for i in range(len(startX)):

        img = cv2.rectangle(img, (startX[i], startY[i]), (endX[i], endY[i]), 255, -1)

    originPath = os.path.splitext(fullPath)

    newPath = originPath[0] + originPath[1]

    cv2.imwrite(newPath, img)

print('finished')