imagedashedline
And to continue what Docey said, if php did not destroy all resources when the script stopped it would be a huge memory leak and everyone would be crying out for it to be fixed right away.
I have been using this function during a script that was breaking an image made of many little icons into the little parts, which could mean 400+ images in the one script, which was using a lot of memory so I needed to destroy them.
imagedestroy
(PHP 4, PHP 5)
imagedestroy — Destroy an image
Description
bool imagedestroy
( resource $image
)
imagedestroy() frees any memory associated with image image .
Parameters
- image
-
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 Using imagedestroy() example
<?php
// create a 100 x 100 image
$im = imagecreatetruecolor(100, 100);
// alter or save the image
// frees image from memory
imagedestroy($im);
?>
add a note
User Contributed Notesimagedestroy
webmaster at codefisher dot org
06-Oct-2007 07:26
06-Oct-2007 07:26
Docey
20-Oct-2006 07:59
20-Oct-2006 07:59
When the script stop PHP will automatic destory ANY
resources, this goes for aswell for images, thus in the
case the use clicks the stop button, php will automatic
clear the resource.
thus imagedestroy is used to clear the memory BEFORE
the script ends. this is usefull to keep memory usage
DURING the script to an acceptable level.
hope this clear somethings up.
roland at more-pc dot nl
25-Sep-2005 03:31
25-Sep-2005 03:31
As Andrew states below, it's IMPERATIVE that you use the imagedestroy() function. But your script may abort before it reaches the call to imagedestroy() (for example the user may click the browsers 'stop' button). In this case the default PHP behaviour is to abort the script, never reaching your call to imagedestroy().
One way of doing it (the one which works very well for me) is with register_shutdown_function():
<?
function shutdown_func() {
global $img;
if($img)
imagedestroy($img);
}
register_shutdown_function("shutdown_func");
$img = imagecreate...(...);
... // manipulate image
// normally I'd need the following line, but now it's handled by shutdown_func()
// imagedestroy($img);
?>
Andrew Hoffmann - ahoffmann at wisc dot edu
23-Jun-2005 04:25
23-Jun-2005 04:25
When working with a lot of high-resolution images, it's IMPERATIVE that you use the imagedestroy() function.
In my scenario, I was taking two high resolution desktop wallpapers and shrinking them down into successively smaller ones (preventing the user from having to upload a dozen files).
At first, my script would run, then just stop. I realized later that I had not destroyed the source image and the newly resized image in memory after I had finished writing the file out to disk. Thus, I quickly reached the memory limit that my hosting provider placed in their php.ini file.
Reusing an image variable does NOT clear the old data out of memory! You must use imagedestroy() to clear the data out. (I don't know if unset() works as well).
Also note that the image data in memory is raw, so don't base how much memory you are using based on the original filesize of the compressed image (such as jpeg or png).
dan at mlodecki dot net
05-Mar-2004 01:42
05-Mar-2004 01:42
I have noticed that gd drawing functions can behave oddly if there is a previous image which has not been imagedestroy()'ed. You should always imagedestroy when you are done with an image object.