How to go from array to list and back again using PIL?

Question

I am trying to put my image in list form in order to insert pixels to the image. However, I'm running into issues on converting back to an image once I've done the list manipulation. Turns out just going from image -> array -> list -> array -> image messes up the image pretty good.

However, going from image -> array -> image seems to work just fine. It's that extra step of going to a list that's causing issues.

Below is the python3 code I'm running. Can anyone tell me what I'm doing wrong and how to get the 3D list converted back into an RGB image that is identical to the original? Both the original and final arrays appear to be the same so not sure what PIL doesn't like...

import numpy as np
from PIL import Image              

img = Image.open('1.jpg') 
array = np.array(img)              

list1 = array.tolist()             
arrayF = np.array(list1)                                                

img2 = Image.fromarray(arrayF,"RGB")
img2.save('trial.jpg')

print(array)
print(arrayF)

Answer 1

If you inspect the dtype of your arrays, with print(array.dtype) , you will see that array is 8-bit and arrayF is 64-bit... which is unacceptable to PIL for an RGB image.

Make arrayF back into 8-bit with:

arrayF = arrayF.astype(np.uint8)