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I'm converting an image to base64 string and sending it from android device to the server. Now, I need to change that string back to an image and save it in the database.

Any help?

Santosh Kumar
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omarsafwany
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5 Answers5

154

Try this:

import base64
imgdata = base64.b64decode(imgstring)
filename = 'some_image.jpg'  # I assume you have a way of picking unique filenames
with open(filename, 'wb') as f:
    f.write(imgdata)
# f gets closed when you exit the with statement
# Now save the value of filename to your database
rmunn
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    @rmunn...what does 'wb' point for?! – omarsafwany May 02 '13 at 01:27
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    @omarsafwany It means "w"rite and "b"inary http://stackoverflow.com/questions/2665866/what-is-the-wb-mean-in-this-code-using-python – HydrUra Dec 16 '13 at 22:26
  • @rmunn : Thanks you so much for those lines ! I know, comments are not made to say thanks but you really save my time ! – HydrUra Dec 16 '13 at 22:28
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    This created a broken image for me. – Josh Usre Dec 07 '15 at 17:39
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    @JoshUsre - If you got a broken image from this sample code, it's probably because the base64 data you're decoding isn't a valid JPEG. It might be a different type of image -- a PNG or a GIF, for example -- and figuring out what kind of image you have is outside the scope of this answer. But try to create a file with the right extension for the kind of image you have, and see if that works. And if you still have trouble, ask a real question rather than dropping a one-sentence comment in a two-year-old post. A real question will get FAR more attention, and better answers. – rmunn Dec 08 '15 at 04:35
  • @rmunn What if I want to display image using opencv? without saving it to any file. – Jumabek Alikhanov Dec 29 '17 at 05:22
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    @JumabekAlikhanov - You should ask a new question about that. Adding a comment to my answer only notifies one person (me), but a new question will be seen by thousands of people, who will probably know opencv much better than I do. From what I've seen of the opencv documentation, I only know how to open an image from a file, so your "without saving it to any file" will need to be answered by someone else. So ask a new question and give enough details, and hopefully someone will know how to do what you're trying to do. – rmunn Dec 29 '17 at 15:34
29

Convert base64_string into opencv (RGB):

from PIL import Image
import cv2

# Take in base64 string and return cv image
def stringToRGB(base64_string):
    imgdata = base64.b64decode(str(base64_string))
    img = Image.open(io.BytesIO(imgdata))
    opencv_img= cv2.cvtColor(np.array(img), cv2.COLOR_BGR2RGB)
    return opencv_img
Jumabek Alikhanov
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    @AbhishekSharma Link only comments are discouraged for a reason that contents might change or disappear at all. Please add your approach as an answer from the next time. – Sachin Jain Oct 13 '19 at 09:08
8

Just use the method .decode('base64') and go to be happy.

You need, too, to detect the mimetype/extension of the image, as you can save it correctly, in a brief example, you can use the code below for a django view:

def receive_image(req):
    image_filename = req.REQUEST["image_filename"] # A field from the Android device
    image_data = req.REQUEST["image_data"].decode("base64") # The data image
    handler = open(image_filename, "wb+")
    handler.write(image_data)
    handler.close()

And, after this, use the file saved as you want.

Simple. Very simple. ;)

Fernando Jorge Mota
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5

This should do the trick:

image = open("image.png", "wb")
image.write(base64string.decode('base64'))
image.close()
pypat
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  • I used this method. I like it because it's pretty much the simplest and closest to the results I want - which is basically turning the string into an image file on disk. – terry franguiadakis May 05 '20 at 09:07
2

You can try using open-cv to save the file since it helps with image type conversions internally. The sample code:

import cv2
import numpy as np

def save(encoded_data, filename):
    nparr = np.fromstring(encoded_data.decode('base64'), np.uint8)
    img = cv2.imdecode(nparr, cv2.IMREAD_ANYCOLOR)
    return cv2.imwrite(filename, img)

Then somewhere in your code you can use it like this:

save(base_64_string, 'testfile.png');
save(base_64_string, 'testfile.jpg');
save(base_64_string, 'testfile.bmp');
Anthony Anyanwu
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