如何使用OpencCV从Firebase读取图像? [英] How to read image from Firebase using OpencCV?

问题描述

是否有使用OpenCV从Firebase读取图像的想法?还是我必须先下载图片，然后从本地文件夹执行cv.imread功能?

Is there any idea for reading image from Firebase using OpenCV? Or do I have to download the pictures first and then do the cv.imread function from the local folder ?

有什么办法可以使用 cv.imread(link_of_picture_from_firebase)?

推荐答案

在这里您可以:

• 从磁盘读取JPEG，
• 转换为JSON，
• 上传到Firebase

那么您可以:

• 从Firebase取回图像
• 将JPEG数据解码回Numpy数组
• 将检索到的图像保存在磁盘上

#!/usr/bin/env python3

import numpy as np
import cv2
from base64 import b64encode, b64decode
import pyrebase

config = {
   "apiKey": "SECRET",
   "authDomain": "SECRET",
   "databaseURL": "SECRET",
   "storageBucket": "SECRET",
   "appId": "SECRET",
   "serviceAccount": "FirebaseCredentials.json"
}

# Initialise and connect to Firebase
firebase = pyrebase.initialize_app(config)
db = firebase.database()

# Read JPEG image from disk...
# ... convert to UTF and JSON
# ... and upload to Firebase
with open("image2.jpg", 'rb') as f:
    data = f.read()
str = b64encode(data).decode('UTF-8')
db.child("image").set({"data": str})


# Retrieve image from Firebase
retrieved = db.child("image").get().val()
retrData = retrieved["data"]
JPEG = b64decode(retrData)

image = cv2.imdecode(np.frombuffer(JPEG,dtype=np.uint8), cv2.IMREAD_COLOR)
cv2.imwrite('result.jpg',image)

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