PIL Not Forming An Image-CodePudding

I am new to PIL, so i was playing around with the functions:

from PIL import Image
import numpy as np
image_array = np.array([   
    [[0, 0, 0],
    [255, 255, 255],
    [0, 0, 0]],
    [[255, 255, 255],
    [0, 0, 0],
    [255, 255, 255]],
    [[0, 0, 0],
    [255, 255, 255],
    [0, 0, 0]]])
image = Image.fromarray(image_array)
image.show()

However, when i want to use it, it gives me the following error in the 13th line: TypeError Cannot handle this data type: (1, 1, 3), <i8 But surprisingly, it doesn't give me an error when i use image_array = np.array(Image.open('Image.png')) which is the exact same image with the exact same array: Image.png (The image is very small, 3 by 3 pixels)

Nobody else seems to have the same problem, or maybe i'm just missing something

CodePudding user response：

Try this with a datatype conversion or define the array with dtype=np.unit8 parameter to begin with.

A relevant answer (different question) can be found here as well. -

img = Image.fromarray(image_array.astype(np.uint8)) #<---
img.width, img.height

(3,3)

Or, simply use np.array([[],[],[]], dtype=np.uint8) to begin with, if memory is an issue.

Further more, if you want to build an array as int64, just use copy=False to return the original array instead of a copy, before you hand it over to PIL.

image_array.astype(np.unit8, copy=False)

CodePudding user response：

When you create your image array with:

image_array = np.array([   
[[0, 0, 0],
[255, 255, 255],
[0, 0, 0]],
[[255, 255, 255],
[0, 0, 0],
[255, 255, 255]],
[[0, 0, 0],
[255, 255, 255],
[0, 0, 0]]])

It will be int64, rather than np.uint8. You can check that with:

print(image_array.dtype)

so it will take 8 times more RAM than necessary. Rather than create something unnecessarily large and then correct it by creating yet another version now requiring 9 times the RAM, I suggest you create it with the correct type in the first place. So, use:

image_array = np.array([   
[[0, 0, 0],
[255, 255, 255],
[0, 0, 0]],
[[255, 255, 255],
[0, 0, 0],
[255, 255, 255]],
[[0, 0, 0],
[255, 255, 255],
[0, 0, 0]]], dtype=np.uint8)