将使用 Streamlit 上传的图像转换为 numpy 数组

Posted 2023-03-29

【中文标题】将使用 Streamlit 上传的图像转换为 numpy 数组

【英文标题】：Turning an image uploaded using Streamlit to a numpy array

【发布时间】：2021-11-26 02:30:18

【问题描述】：

我正在使用 Streamlit 为机器学习项目开发一个 web 应用程序。

我在load_img 遇到了这个错误：

TypeError: expected str, bytes or os.PathLike object, not UploadedFile.

from tensorflow.keras.models import load_model
from tensorflow.keras.preprocessing.image import load_img
from tensorflow.keras.preprocessing.image import img_to_array
from tensorflow.keras.applications.vgg16 import preprocess_input
from tensorflow.keras.applications.vgg16 import decode_predictions
from tensorflow.keras.applications.vgg16 import VGG16
from tensorflow.keras.models import model_from_json
import numpy as np
import cv2
import tensorflow as tf
import streamlit as st


st.write("This is a simple image classification web app to identify cars")
file = st.file_uploader("Please upload an image file", type=["jpg", "png"])


def import_and_predict(image_data, model):

        image = load_img(image_data,target_size=(64,64))  

        img = img_to_array(image)

        img = np.array(image) 
        img = img / 255.0
        image = img.resize((64,64))

        img = img.reshape(1,64,64,3)
        label = model.predict_classes(img)
    
        prediction = label[0][0]
        
        return f"Prediction: prediction" 

if file is None:
    st.text("Please upload an image file")
else:
    import_and_predict(file, model)

【参考方案1】：

来自Streamlit documentation for file_uploader：

>>> uploaded_file = st.file_uploader("Choose a file")
>>> if uploaded_file is not None:
...     # To read file as bytes:
...     bytes_data = uploaded_file.getvalue()
...     st.write(bytes_data)

上面的代码会给你一个 BytesIO 对象，然后可以将其转换为表示图像的数组。