Image 24 bit depth to 8 bit depth

import os
import cv2
import numpy as np

labels_path = 'label_5_class_png_1024_1024'
labels_save_path = 'label_5_class_png_1024_1024_1'
//  Get all the files in the folder 
label_names = os.listdir(labels_path)
for s in label_names:
    label_path = os.path.join(labels_path, s)
    label_save_path = os.path.join(labels_save_path, s)
    //  Read the file 
    label = cv2.imread(label_path)
	// 24 Bit depth turn 8 Bit depth 
    label = cv.cvtColor(label, cv.COLOR_BGR2GRAY)
    //  Save the file 
    cv2.imwrite(label_save_path, label)