Check if image is empty php

Question

i'm trying to make a php script to get a user picture but when i the returned image is empty, it should return the standard image. This is the code i have that does not work...

<?php
if (isset($_GET['user']))
{
$user = $_GET['user'];
$skinURL = "http://s3.amazonaws.com/MinecraftSkins/".$user.".png";
} 
$debugImage = imagecreatefrompng("http://s3.amazonaws.com/MinecraftSkins/".$user.".png");
if (empty($debugImage)) // here it checks if $debugImage is empty (doesn't work)
{
    $skinURL = 'http://www.minecraft.net/images/char.png';
}
$skin = imagecreatefrompng($skinURL);
?>

any ideas?

edit 1: The link returns a image if it exists, and nothing if it doesn't exist. Thanks already for the answers!

Did try with the static url like: `http://s3.amazonaws.com/MinecraftSkins/user.png` — Rahil Wazir, Dec 21 '13 at 11:03
Maybe imagecreatefrompng doesn't return an empty variable. Could you check the length of $debugImage? — Dan Goodspeed, Dec 21 '13 at 11:03
@LordVoldemort it doesn't return any image if it doesn't exist. — Robbe7730, Dec 22 '13 at 08:33
@RahilWazir i do not need the static url i need a user skin depending on the input — Robbe7730, Dec 22 '13 at 08:34

score 6 · Answer 1 · edited Jun 20 '20 at 09:12

There's no such thing as "empty image". Even if it's a blank image there are still pixels with the same color, which would be hard to classify as "empty". Instead why not checking if the file exists?

function c_file_exists($file){
    $file_headers = @get_headers($file);
    if(strpos($file_headers[0], '404 Not Found')) {
        return false;
    }
    return true;
}
if (!c_file_exists("http://s3.amazonaws.com/MinecraftSkins/".$user.".png"))
{
    $skinURL = 'http://www.minecraft.net/images/char.png';
}

Source: http://www.php.net/manual/en/function.file-exists.php#75064

EDIT

I edited the condition of the function to work with different versions of HTTP as 2 is out now and someone may still be using 1.0

Well it's actually just no image at all when the user doesn't exist, but still thanks for the reply! (sorry for me being so late in my comments) — Robbe7730, Dec 22 '13 at 08:31

score 0 · Answer 2 · edited May 23 '17 at 12:29

0

Two things to note here:

First, ensure allow_url_fopen is enabled in your environmental settings

Secondly, add a check to ensure that the remote file exists. You could make a curl request to do this. Or use the method php_nub_qq mentions in his answer.

Better yet, copy the remote image to your server before calling imagecreatefrompng. Take a look at this thread

edited May 23 '17 at 12:29

Community

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answered Dec 21 '13 at 11:15

dnshio

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Check if image is empty php

2 Answers2

EDIT