How to store Images in MongoDB through pymongo? - mongodb

Question

from PIL import Image
from bson import Binary
img = Image.open('test.jpg')
img = Binary(img)
throws an error stating TypeError : data must be an instance of bytes
Why does this happen? And how to resolve this to store the img to MongoDB?

Answer 1

As long as the document doesn't exceed 16MB standard bson is fine, otherwise gridfs should be used. The example below shows how an image can be inserted and read back from a mongodb.
insert_image.py
from pymongo import MongoClient
from PIL import Image
import io
client = MongoClient()
db = client.testdb
images = db.images
im = Image.open("./image.jpg")
image_bytes = io.BytesIO()
im.save(image_bytes, format='JPEG')
image = {
'data': image_bytes.getvalue()
}
image_id = images.insert_one(image).inserted_id
read_image.py
from pymongo import MongoClient
from bson.binary import Binary
from PIL import Image
import io
import matplotlib.pyplot as plt
client = MongoClient()
db = client.testdb
images = db.images
image = images.find_one()
pil_img = Image.open(io.BytesIO(image['data']))
plt.imshow(pil_img)
plt.show()

Answer 2

You need to convert the image into a Byte array. You can do this as follows,
from PIL import Image
from bson import Binary
img = Image.open('test.jpg')
imgByteArr = io.BytesIO()
img.save(imgByteArr, format='PNG')
imgByteArr = imgByteArr.getvalue()
You can try to save imgByteArr into mongo
OR
You can convert image into string and then store it in mongo:
import base64
with open("test.jpg", "rb") as imageFile:
str = base64.b64encode(imageFile.read())
//store str in mongo
To get back image
with open("test2.jpg", "wb") as fimage:
fimage.write(str.decode('base64'))