将Base64编码的图像上载到PHP服务器

Question

I'm trying to upload a Base64 encoded .Png file to a PHP server from an Android application.

Below code doesn't return anything in the response. What am I doing wrong?

I'm sending the Base64 encoded string and the name of the file. (ex:"sign1234.png")

<?php

if(isset($_POST['image']) && isset($_POST['name']){

$image = $_POST['image'];
$name = $_POST['name'];

$png = base64_to_jpeg($image,$name);

$target = 'uploads/'.$name;
$result = move_uploaded_file( $_FILES['$png']['tmp_name'], $target);

if($result){
        $response["success"] = 1;
        $response["message"] = "Upload Successful.";
        echo json_encode($response);
}else{
    $response["success"] = 0;
    $response["message"] = "Server error. Could not upload.";
    echo json_encode($response);
}

}

function base64_to_jpeg($base64_string, $output_file) {
    $ifp = fopen($output_file, "wb"); 

$data = explode(',', $base64_string);

fwrite($ifp, base64_decode($data[1])); 
fclose($ifp); 

return $output_file; 
}
?>