如何通过 pymongo 将图像存储在 MongoDB 中？

Question

from PIL import Image
from bson import Binary

img = Image.open('test.jpg')
img = Binary(img)

抛出一个错误声明TypeError : data must be an instance of bytes

为什么会这样？以及如何解决这个问题以将 img 存储到 MongoDB？

Answer 1

只要文档不超过 16MB 标准 bson 就可以了，否则应该使用 gridfs。下面的例子展示了如何在 mongodb 中插入和读回图像。

插入图像.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

您需要将图像转换为字节数组。你可以这样做，

from PIL import Image
from bson import Binary

img = Image.open('test.jpg')

imgByteArr = io.BytesIO()
img.save(imgByteArr, format='PNG')
imgByteArr = imgByteArr.getvalue()

您可以尝试将 imgByteArr 保存到 mongo 中

或

你可以将图片转换成字符串，然后存储在mongo中：

import base64

with open("test.jpg", "rb") as imageFile:
    str = base64.b64encode(imageFile.read())
    //store str in mongo

获取图片

with open("test2.jpg", "wb") as fimage:
    fimage.write(str.decode('base64'))