Joining edited images in python using numpy image slicer - image

Question

I am learning image manipulation as a beginner in python. My goal is to section my image into an nxn grid where each square is the average color (greyscale image) of the original, respectively. I succeeded in splitting the image, changing its pixel data and saving the new images. My problem is now stitching the image back together. I know the join function is pointing back to the original image, I had hoped that by saving over the tiles I could work around this.
This is my first time posting to stackoverflow (and I am super, super new to python), so apologies if I am not clear or if the formatting is wrong.
# Import packages
import numpy as np
from numpy import matlib
import PIL
import image_slicer
import math
import glob
from image_slicer import join
from PIL import Image
### Use PIL to import image
##img = Image.open("einstein.jpg")
# Display original image
# img.show()
##new_img = img.resize((256,256))
##new_img.save('einstein-256x256','png')
### new_img.show()
#Slice image into four pieces
tiles = image_slicer.slice("einstein.jpg", 16)
# Use glob to open every .png file with for loop
for filename in glob.glob("*.png"):
img=Image.open(filename)
pixels = img.load() # create the pixel map
pixelMap = img.load() #create the pixel map
#convert to array
arr = np.asarray(img)
#find mean
pixelMean = arr.mean(0).mean(0)[0]
# Convert mean to integer
IntMean = math.floor(pixelMean)
print(IntMean)
##pixel = pixelMap[0,0] #get the first pixel's value
##print(pixel)
# Loop for going through every pixel in image and converting it
for i in range(img.size[0]): # for every col:
for j in range(img.size[1]): # For every row
pixels[i,j] = (IntMean,IntMean,IntMean) # set the colour accordingly
# Save new monotone images
img.save(filename)
# Join new images into one
image = join(tiles)
# Save new image
image.save("einsteinJoined.jpg")
image.show()

Answer 1

Your question seems to be missing the error you get with your current code.
However, if I read it correctly, you will get back your original image, as was the problem in Split and Join images in Python. Similar to the answer accepted there, the solution is to change the image in each tile by ending your loop with:
tile.image = Image.open(filename)
Where tile is the tile corresponding to the file, you should loop over the tiles from the image_slicer.slice-function to do so. This is also given in answer to the question linked to.