python: convert base64 encoded png image to jpg

Question

I want to convert some base64 encoded png images to jpg using python. I know how to decode from base64 back to raw:

import base64 
pngraw = base64.decodestring(png_b64text)

but how can I convert this now to jpg? Just writing pngraw to a file obviously only gives me a png file. I know I can use PIL, but HOW exactly would I do it? Thanks!

Please remember to accept answers to your questions. You've only done that for one of your last ten questions. — agf, Aug 06 '11 at 10:44
You know the process you applied to figure out how to use the `base64` module? Why not apply it to `PIL` as well? — Karl Knechtel, Aug 06 '11 at 11:58

phihag · Accepted Answer · 2011-08-06T12:41:04.993

21

You can use PIL:

data = b'''iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAAXNSR0IArs4c6QAAAIBJRE
          FUOMvN08ENgCAMheG/TGniEo7iEiZuqTeiUkoLHORK++Ul8ODPZ92XS2ZiADITmwI+sWHwi
          w2BGtYN1jCAZF1GMYDkGfJix3ZK8g57sJywteTFClBbjmAq+ESiGIBEX9nCqgl7sfyxIykt
          7NUUD9rCiupZqAdTu6yhXgzgBtNFSXQ1+FPTAAAAAElFTkSuQmCC'''

import base64
from PIL import Image
from io import BytesIO

im = Image.open(BytesIO(base64.b64decode(data)))
im.save('accept.jpg', 'JPEG')

In very old Python versions (2.5 and older), replace b''' with ''' and from io import BytesIO with from StringIO import StringIO.

edited Aug 06 '11 at 12:41

answered Aug 06 '11 at 10:37

phihag

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I had to `pip install Pillow` in order to `import PIL` http://stackoverflow.com/questions/20060096/installing-pil-with-pip – Matthew Moisen Oct 03 '16 at 02:38

score 4 · Answer 2 · answered Aug 06 '11 at 10:41

Right from the PIL tutorial:

To save a file, use the save method of the Image class. When saving files, the name becomes important. Unless you specify the format, the library uses the filename extension to discover which file storage format to use.

Convert files to JPEG

import os, sys
import Image

for infile in sys.argv[1:]:
    f, e = os.path.splitext(infile)
    outfile = f + ".jpg"
    if infile != outfile:
        try:
            Image.open(infile).save(outfile)
        except IOError:
            print "cannot convert", infile

So all you have to do is set the file extension to .jpeg or .jpg and it will convert the image automatically.

python: convert base64 encoded png image to jpg

2 Answers2

Convert files to JPEG

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