python - Open PIL image from byte file

Question

I have this image with size 128 x 128 pixels and RGBA stored as byte values in my memory. But

from PIL import Image

image_data = ... # byte values of the image
image = Image.frombytes('RGBA', (128,128), image_data)
image.show()

throws the exception

ValueError: not enough image data

Why? What am I doing wrong?

the raw data in a .png file has headers and compression and stuff, so I don't think you can feed it into frombytes and get a coherent result. — Kevin
I guess you could open the image with Image.open("homer.jpg"), and then call tobytes on it to get a buffer suitable for passing to frombytes... But there's not much point in doing image = Image.frombytes(Image.open("homer.jpg").tobytes()) when you can just do image = Image.open("homer.jpg"). I'm assuming your actual use case is more complicated and you can't do the latter for some reason. — Kevin
So your actual question is "how do I read data from a socket?"? — Kevin
No, this works already. But instead of socket -> store image to file -> load from this file -> done I want socket -> done . I tried to make the question a little bit more clear! — Michael Dorner

Colonel Thirty Two Colonel Thirty Two · Accepted Answer · 2015-10-02T13:59:16

The documentation for Image.open says that it can accept a file-like object, so you should be able to pass in a io.BytesIO object created from the bytes object containing the encoded image:

from PIL import Image
import io

image_data = ... # byte values of the image
image = Image.open(io.BytesIO(image_data))
image.show()

python - Open PIL image from byte file

2 Answers