PHP - Image Check

What is the best/proper way to check if a supplied URL goes to an actual image?  My site will allow users to enter an image URL (like "http://example.com/images/monkey.jpg").  I will store the URL they enter in a MySQL database and then will call it up later and do some resizing to these images. 

But I don't want to try to do any resizing if the URL they supply doesn't actually go to an image, or if it's blank (i.e. the user didn't enter a URL yet). 

So basically, I will run a MySql query to pull back the contents of the column called "imageurl".  Let's say those contents are stored in a variable called $imageurl.  This is what I'm trying to accomplish....

Code: [Select]
if ($theimageurl does NOT contain a URL to an image OR is blank) {
// do this
} else {
//run my resizing code
}
I guess i could do this to check to see if it's blank, but not sure this is proper/most efficient way to check that part of the issue...

Code: [Select]
if (trim($theimageurl) == "")
But greater than the "is it blank" concern is that people may enter URLs that just to a regular website so whether it's at this point in my code (or for security, I should probably do it BEFORE inserting it into my database :/ ) so curious if there are any functions that check to see if it's an image URL or not.  I know of file_exists, but I'm pretty sure that's just checking to see if a file exists and doesn't check image URLs.

Any info/suggestions would be appreciated as always! 

And if there are any recommended functions to check/clean the user-entered URL BEFORE it's entered into the database, please share

Thanks!

Hi,
I have an image handling php script which works fine here if the image is actually a readable format by the php program...
Code: [Select]
<?php
//determine image type
if($this->ext == 'jpeg' || $this->ext == 'jpg') 
{
$imageObject = imagecreatefromjpeg($image); 
}
               elseif($this->ext == 'gif') 
{ 
$imageObject = imagecreatefromgif($image);
}
?>


However, I tested the script with a random gif created in photoshop and i got an ugly php error returned saying the image was not the correct type for imagecreatefromgif even tho the image was a .gif file.

In response I then tried to make a safety test, but it doesn't seem to work:
Code: [Select]
<?php
//determine image type
if($this->ext == 'jpeg' || $this->ext == 'jpg') 
{
if(imagecreatefromjpeg($image))
{
$imageObject = imagecreatefromjpeg($image); 
}
else{
//now remove the old TEMP file ($image)
unlink($image);
return 'Sorry there is a file type error with the image you are uploading.';*/
}
}
                elseif($this->ext == 'gif') 
{ 
if(imagecreatefromjpeg($image))
{
$imageObject = imagecreatefromgif($image);
}
else{
//now remove the old TEMP file ($image)
unlink($image);
return 'Sorry there is a file type error with the image you are uploading.';*/
}
}
?>

The $image can be either a jpg jpeg gif or png...

Could anyone please tell me how to correctly check if the file is in readable by the php program in this context?
Any help would be very much appreciated

Hello,

i want to check whether image exist or not, but i can't get any data about it. I have tried everything: getimagesize, file_exist, filesize, etc.

<?

$info = @getimagesize('http://jargames.eu/ic.php?lf=files/All phone/240x320/007-quantum_of_solace_240x320.jar');
if(isset($info['mime'])){echo 'Image exist';}
else{echo 'Image doesnt exist';}

?>
Ty, for your help.

 
Please help before this script drives me insane.
It tries to download a skin from Minecraft.

It works fine, except, if it returns an error code, (301, 302, 404), don't download, and using my image (char.png) as a replacement.
I can get the error code, except, no matter how I compare it, it will a) still say it's 302 or b) not work at all.


Here's my code:

userskin.inc.php >
<?php
require('class.mineuser.php');
if(!isset($_GET['width']) || strlen(trim($_GET['width'])) == 0 || !isset($_GET['height']) || strlen(trim($_GET['height'])) == 0) {
$x = 16;
$y = 16;
} else {
$x = $_GET['width'];
$y = $_GET['height'];
}

if(isset($_GET['refresh'])) 
$refresh = true;
else
$refresh = false;

if(isset($_GET['debug'])) 
$debug = true;
else
$debug = false;

$http = curl_init("http://www.minecraft.net/skin/{$_GET['user']}.png");
curl_setopt($http, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($http);
$http_status = curl_getinfo($http, CURLINFO_HTTP_CODE);
$resp = preg_match("/302/", $http_status, $match);
$code = $match[0];
if($code == 302) {
mineuser::downloadSkin($_GET['user'], $_GET['path'], $code, $refresh);
mineuser::getFace($_GET['user'].".png", $x, $y, $_GET['path'], $code, $debug);
} else {
mineuser::getFace("char.png", $x, $y, $_GET['path'], $code, $debug);
}

class.mineuser.php >
<?php
class mineuser {
public static function downloadSkin($user, $path = "", $resp, $new = false) {
if($resp !== 302) {
//Checks if $new is true, if it is, then delete $user.png and download a new one.
if($new == true) unlink("$path/$user.png");

//Checks if the users skin already exists (faster loading time)
if(!file_exists("$path/$user.png")) { 
$fh = fopen("$path/$user.png", "w"); 
$file = file("http://www.minecraft.net/skin/$user.png");

foreach($file as $char) //Since it's an array, we use a foreach loop and write each character individually
fwrite($fh, $char);

fclose($fh); //Close our file handler. 
}
} else {

}
} //End of function downloadSkin()

public static function getFace($user, $width, $height, $path, $resp, $debug = true) {
$im = imagecreatetruecolor($width, $height);
if($debug == false) {
header("Content-type: image/png");
}
if($resp === 302) {
$image = imagecreatefrompng("$path/char.png");
} else {
$image = imagecreatefrompng("$path/$user");
}
imagecopyresampled($im, $image, 0, 0, 8, 8, $width, $height, 8, 8);

imagepng($im);
imagedestroy($im);

} //End of function getFace()
}
?>


please help before i go insane 

Thanks in advance 

I use a script for sharing links. Everything works ok, but checking for valid images can take a long time.
First through CURL method I parse certain tags (for description and title) then I use the following script to find images from the submited link:

Code: [Select]
$dom = new domDocument;
  @$dom->loadHTML('<?xml encoding="UTF-8">' . substr($content,0,35000));
  $dom->preserveWhiteSpace = false;
  $images = $dom->getElementsByTagName('img');

It sometimes happens that the images have not not a good path(depending on whether the link is permanent or not) and then use the getimagesize function that works well. But it can be very slow ...sometimes it takes 15-30 seconds.
Without function getimagesize process takes a few seconds.
Is there a better (faster) method to check whether the image is valid or not?