使用Azure Blob存儲中的圖像作為輸入

Question

我正在一個項目中，在該項目中，我使用構建的keras模型對存儲在Azure Blob存儲中的圖像進行分類並將結果導出為.csv文件。 通過使用get_blob_to_path並將一些圖像下載到我的筆記本電腦上，我能夠做到這一點。 但是，由於圖片太多，因此我希望不通過get_blob_to_bytes或get_blob_to_stream下載圖片。

Answer 1

實際上，一種無需先下載就從Azure Blob存儲加載圖像的更簡單解決方案是使用sas令牌生成blob url，並將其傳遞給imageio.imread 。

這是我的代碼從您的代碼更改而來。

from azure.storage.blob import BlockBlobService
from azure.storage.blob import ContainerPermissions
from datetime import datetime, timedelta

import imageio
import numpy as np
from skimage import transform
import pandas as pd

account_name = '<your account name>'
account_key = '<your account key>'
container_name = '<your container name>'

# generate the container-level sas token 

block_blob_service = BlockBlobService(account_name=account_name, account_key=account_key)
token = block_blob_service.generate_container_shared_access_signature(container_name, permission=ContainerPermissions.READ, expiry=datetime.utcnow() + timedelta(hours=1),)

# generate the list of blob urls with sas token

blob_names = service.list_blob_names(container_name)
df = pd.read_csv("~/Desktop/list.csv")
blob_urls_with_token = (f"https://{account_name}.blob.core.windows.net/{container_name}/{blob_name}?{token}" for blob_name in blob_names if blob_name in df.values)

#function to prepare the image for keras model

def load(img_sas_url):
    image = imageio.imread(img_sas_url)  # directly read image from the blob url with sas token
    image = np.array(image).astype('float32')/255
    image = transform.resize(image, (224, 224, 3))
    image = np.expand_dims(image, axis=0)
    return image

#predicting the images and append it to a datafram

predictions = []
images=[]
name = []
probs =[]
for img_sas_url in blob_urls_with_token:
    image = load(img_sas_url)
    prediction = model.predict_classes(image)
    prob = model.predict(image).max()
    predictions.append(prediction)
    probs.append(prob)
    images.append(file)
    name.append(root.split('\\')[4])

output = pd.DataFrame(
{'ImageID':name,
 'ImageName':images,
 'Predictions':predictions,
 'Probabilities':probs
})

希望能幫助到你。