我正在创建一个注册系统，其中将根据用户的输入创建一个文件夹，并将为该人将图像放入该文件夹中。文件夹已创建，但图像只是一个空的 jpg 文件。
注册.php：
<!DOCTYPE>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Register</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/webcamjs/1.0.25/webcam.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.1.3/css/bootstrap.min.css" />
<style type="text/css">
#results {
padding:20px;
border:1px solid;
background:#ccc;
}
#my_camera {
transform: rotateY(180deg);
}
</style>
</head>
<body>
<div >
<form method="POST" action="saveimage.php">
<div>
<h1>Register</h1>
<p>Please fill in this form to register yourself.</p>
<hr>
<label for="username"><b>Name</b></label>
<input type="text" placeholder="Enter Name" name="username" required>
<hr>
<div >
<div id="my_camera"></div>
<br/>
<input type=button value="Take Snapshot" onClick="take_snapshot()">
<input type="hidden" …