CODEWITHSUNDEEP
pythonnumpypython-imaging-library
Roland Deschain
Roland Deschain

Reputation: 2830

How to read a png image from an encoded bytearray and store it into a numpy array?

My python socked receives a PNG image as encoded bytearray. The image originally has RGBA32 format and a resolution of 160 x 90. After encoding it, I receive a bytearray with a length of 31529 (as opposed to the raw data size, which should be 160 * 90 * 4 = 57600) bytes.

How can I decode this bytearray again and 1) display it with the PIL library and 2) convert it to a numpy array to work with the data?

I tried using the Image module from PIL (with received_data being my bytearray):

import PIL.Image as Image
# socket code...
Image.frombytes('RGBA', (160, 90), received_data)

but get the following error:

argument 1 must be read-only bytes-like object, not bytearray

Edit: Following @thshea suggestion, I changed the code to Image.frombytes('RGBA', (160, 90), bytes(received_data)), which resolves the error above. However, the function still seems to expect raw image data and I get the this error:

not enough image data

Furthermore, I think this is meant to take raw data, with the option to write a custom decoder?

Upvotes: 0

Views: 1598

Answers (1)

Ture Pålsson
Ture Pålsson

Reputation: 6776

There's probably some better way, but wrapping the bytearray in a BytesIO object and giving it to PIL as an open file should do it:

import io
f = io.BytesIO(received_data)
im = Image.open(f)

Upvotes: 1

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