Bad Request 400 uploading images to the imgur API - php

Question

I want to upload some pictures with the imgur-API to imgur, but I am always getting an Error 400 Bad Request. Whats the issue?
<?php
if (isset($_POST['uploadprofileimg'])) {
$image = base64_encode(file_get_contents($_FILES['profileimg']['tmp_name']));
$options = array('http'=>array(
'method'=>"POST",
'header'=>"Authorization: Bearer *MY_ACCESS_TOKEN*\n".
"Content-Type: application/x-www-form-urlencoded",
'content'=>$image
));
$context = stream_context_create($options);
$imgurURL = "https://api.imgur.com/3/image";
$response = file_get_contents($imgurURL, false, $context);
}
?>
<h1>My Account</h1>
<form action="upload-pb.php" method="post" enctype="multipart/form-data">
Upload a profile image:
<input type="file" name="profileimg">
<input type="submit" name="uploadprofileimg" value="Upload Image">
</form>

Answer 1

Looking at the endpoint for /image here, it needs a parameter of image. You're passing it in as content, and not properly encoded as image. Looking here, I borrowed how to properly upload content using stream_context_create/file_get_contents:
<?php
if (isset($_POST['uploadprofileimg'])) {
$image = base64_encode(file_get_contents($_FILES['profileimg']['tmp_name']));
$postdata = http_build_query(
array(
'image' => $image,
)
);
$options = array('http'=>array(
'method'=>"POST",
'header'=>"Authorization: Bearer *MY_ACCESS_TOKEN*\n".
"Content-Type: application/x-www-form-urlencoded",
'content' => $postdata
));
$context = stream_context_create($options);
$imgurURL = "https://api.imgur.com/3/image";
$response = file_get_contents($imgurURL, false, $context);