PHP Imagick memory leak

Question

I have to render something with Imagick on PHP CLI. I have noticed that every 3-5 days the server memory gets full, so i can't even connet via ssh or ftp.

with memory_get_usage() i narrwoed the memory leak down to the imagick part of the script. the script looks something like this:

$sourceImg = 'source.png';
$destImg = 'dest.png';
$background ='#00ff00';

$im = new Imagick();
$im->pingImage($sourceImg);
$im->readImage($sourceImg); 
$draw = new ImagickDraw();

for($i=1;$i<=5;$i++){
    $draw->setFillColor( $background);
    $draw->rectangle( 10*$i+5, 10, 10*$i+10, 20);
} 

$im->drawImage( $draw );
$im->writeImage( $destImg );
$im->destroy();

unset($im,$draw);

I destroy the image reference, and unset the imagick and imagickDraw object, but the script won't release any memory. The setFillColor() method takes the most memory

Can i do something else to free the space used by imageick?

image of the memory consumption

MattBianco · Accepted Answer · 2014-02-14T09:18:34.640

imagick uses a shared library and it's memory usage is out of reach for PHP, so tuning PHP memory and garbage collection won't help.

I had the same problem myself, trying to handle a multi-page-tiff image with 50 (!) pages of 3000x2000 pixels. The solution is to have imagick put its pixel cache on disk.

Adding this prior to creating the Imagick object solved the problem for me:

// pixel cache max size
IMagick::setResourceLimit(imagick::RESOURCETYPE_MEMORY, 256);
// maximum amount of memory map to allocate for the pixel cache
IMagick::setResourceLimit(imagick::RESOURCETYPE_MAP, 256);

The goal is to make imagick put its pixel cache on disk instead of in RAM. The default place seems to be files /tmp/magick-XXnnnnn, so make sure /tmp is not on shmfs/ramdisk, or change the temp directory imagick uses.

Other resouce limits to investigate: imagick::RESOURCETYPE_DISK, imagick::RESOURCETYPE_FILE, and imagick::RESOURCETYPE_AREA. They are described in the imagick::getResourceLimit() manual page (not so well in the page for setResourceLimit()).

In my image handling loop, I have set_time_limit(300), since the script takes ages to process this huge (when uncompress) image.

EDIT : In recent versions, setResourceLimit() should not be called as a static method, but on the actual object instead, such as:

$im->setResourceLimit(imagick::RESOURCETYPE_MEMORY, 256);
$im->setResourceLimit(imagick::RESOURCETYPE_MAP, 256);
$im->setResourceLimit(imagick::RESOURCETYPE_AREA, 1512);
$im->setResourceLimit(imagick::RESOURCETYPE_FILE, 768);
$im->setResourceLimit(imagick::RESOURCETYPE_DISK, -1);

i already gave up on this problem. but this solution works great. thanks — Slemgrim, Oct 27 '12 at 20:14
So it will fill the disk instead the RAM? What is this cache? — Thomas Decaux, Jun 03 '14 at 17:23
Yes. Putting the pixel cache on disk is necessary when RAM is too small. Think of the pixel cache for ImageMagick as virtual memory used for image manipulation and temporary storage. — MattBianco, Jun 04 '14 at 12:41
Note: according to the RESOURCETYPE constant documentation, the limits should be set in bytes, not megabytes, so 256 should be 256 * 1024 * 1024 if you want the limit to be 256 MB. — Kevin Borders, Oct 06 '20 at 17:18

score 7 · Answer 2 · answered Jun 23 '15 at 11:54

I know this is old but I ran into the same problem and calling $im->clear() instead of $im->destroy() fixed the memory leak for me.

According to the documentation Imagick::destroy() has been deprecated in favor of Imagick::clear(). So clear() should be used.

score 2 · Answer 3 · answered Jun 03 '20 at 23:27

You can use this.

Note that clear() is preferred over destroy() according to the docs to release memory use.

// clear temp files
$imagick_image->clear(); // in your case "$img->clear();"

You can also run a cron to delete the temp files for you, otherwise your server could crash. This is not php code, it is command line code.

# linux command
find /tmp/ -name "magick-*" -type f -delete

# cron
45 * * * * find /tmp/ -name "magick-*" -type f -delete

score 1 · Answer 4 · answered Apr 03 '12 at 20:17

xdebug wasn't able to help me.. so i decided do look out for another solution. i came up with using image magic direct:

$sourceImg = 'source.png';
$destImg = 'dest.png';
$background ='#00ff00';

$command = "convert {$sourceImg}";
$out = array();

for($i=1;$i<=5;$i++){
    $command .= " -fill \"{$background}\" ";
    $command .= " -draw 'rectangle {$x1},{$y1} {$x2},{$y2}'";
} 

$command .= " {$destImg}";
exec($command,$out);

this solutions works way smoother then the imagick one. but i don't like the error-prone code.

Hmm well it certainly works, but aside from the uglyness of calling shell commands from within php, on some production servers exec is actually disabled for security reasons. — Toumal, Mar 03 '13 at 13:49

PHP Imagick memory leak

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