Python / PIL: Create and save image from data uri

Question

I have a url like so

data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wCEAAkGBxITEhUUEhQUFRUXGBcVFxgXFxUXGBQYGBYXGBQWFRUYHCggGB0lHBQXITIhJSkrLi4uFyAzODMsN         


        

Answer 1

I will assume you have just the base64 part saved in a variable called data. You want to use Python's binascii module.

from binascii import a2b_base64

data = 'MY BASE64-ENCODED STRING'
binary_data = a2b_base64(data)

fd = open('image.png', 'wb')
fd.write(binary_data)
fd.close()

No PIL needed! (thank goodness! :)

Answer 2

To expand on the comment from Stephen Emslie, in Python 3 this works and is less code:

data = 'data:image/jpeg;base64,iVBORw0KGgoAAAANSUhEUAAAhwAAAFoCAYAAAA.......'
response = urllib.request.urlopen(data)
with open('image.jpg', 'wb') as f:
    f.write(response.file.read())

Answer 3

There's nothing in the stdlib to parse data: URIs beyond pulling out the path. But it's not hard to parse the rest yourself. For example:

import urllib.parse

up = urllib.parse.urlparse(url)
head, data = up.path.split(',', 1)
bits = head.split(';')
mime_type = bits[0] if bits[0] else 'text/plain'
charset, b64 = 'ASCII', False
for bit in bits:
    if bit.startswith('charset='):
        charset = bit[8:]
    elif bit == 'base64':
        b64 = True

# Do something smart with charset and b64 instead of assuming
plaindata = data.decode("base64")

# Do something smart with mime_type
with open('spam.jpg', 'wb') as f:
    f.write(plaindata)

(For Python 2.x, just change urllib.parse to urlparse.)

Notice that I didn't use PIL at all. You don't need PIL to save raw image data to a file. If you want to make an Image object out of it first, e.g., to do some post-processing, of course you can, but it's not relevant to your question.