我正在学习flask，尝试编写图像中边缘检测的代码，并让用户上传图像，使用flask。我相信我无法正确上传图像，当我单击上传时，它显示“未选择文件”。这是我的代码。
import os.path
from io import BytesIO
from tempfile import mkdtemp
from flask import Flask, render_template, flash, request
from flask import send_from_directory, redirect, send_file
from werkzeug.utils import secure_filename
from edge_new import edge_detector
from flask_app import UPLOAD_FOLDER
app = Flask(__name__)
app.secret_key = 'sib'
temp_dir = mkdtemp()
app.config[UPLOAD_FOLDER] = 'temp_dir'
@app.route('/')
def hello():
return "The app is up and running. Go to /edge for functionality"
@app.route('/edge', methods=['POST', 'GET'])
def process_img():
"""
Function takes an image,
finds edges in the image,
returns processed image for download.
"""
if request.method == 'POST':
# Check if image exists
if 'img' not in request.files:
flash("Image not found"), 400
return redirect('/edge')
image = request.files['img']
# Check if image selected
if image.filename == "":
flash("No selected image"), 400
return redirect('/edge')
# Save the image
image_path = secure_filename(image.filename)
path = os.path.join(temp_dir, image_path)
image.save(path)
# Find edges in the image using edge_detector function
processed_image = edge_detector(path) # processed_img is ndarray
# Save the processed image
send_file(BytesIO(processed_image), download_name='processed.jpg', mimetype='image/jpg', as_attachment=True)
return render_template('index.html')
if __name__ == '__main__':
app.run(host='0.0.0.0', port=3000, debug=True)
我尝试过不同的事情。但错误仍然存在。我尝试过 send_file()、send_from_directory()、cv2.imwrite() 但我不确定什么有效。这是我的index.html代码。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>File Upload Example</title>
<style>
.ok{
font-size: 20px;
}
.op{
font-size: 20px;
margin-left: -70px;
font-weight: bold;
background-color: yellow;
border-radius: 5px;
cursor: pointer;
}
</style>
</head>
<body>
<div class="center">
<h1> Uploading and Returning Files With a Database in Flask </h1>
<form method="POST" action="/edge" enctype="multipart/form-data">
<input class="ok" type="file" name="file">
<button class="op">Submit</button>
</form>
</div>
</body>
</html>
可以使用 name 属性查询输入字段的值。不幸的是，您已经为输入字段设置了属性
fileimgrequest.filesimgfile我通过运行检查了你的代码。 您的端点 /edge 正在尝试在 if 条件下获取 img 并阻止：
if 'img' not in request.files:
flash("Image not found"), 400
return redirect('/edge')
image = request.files['img']
当您以 name="file" 的形式发送文件时
<input class="ok" type="file" name="file">
您可以通过更新index.html输入代码行来纠正它： （参见 name="img" 而不是 name="file"）
<input class="ok" type="file" name="img">
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