Handles image processing on request instead of during page generation

1.0.2 2021-02-24 10:55 UTC

This package is auto-updated.

Last update: 2021-04-10 09:04:18 UTC


What does it do?

The extension defers the image processing from during page generation to when the image is actually requested from the client (browser). When the image is processed and placed in the storage's processed folder, it will not be processed again, until it is deleted or all processed images are cleared.

This is useful on sites with lots of images on one page. Instead of generating one image after another, leading to a massive delay in page generation speed, the image processing load is split to the available PHP processes and thereby to multiple CPU cores.

Installation & configuration

The extension is available from packagist.org

composer require webcoast/deferred-image-processing

or from TYPO3 extension repository.

A database update is necessary to create the processing queue table.

Rewrite rules for apache

If using the default htaccess file which is shipped with TYPO3, then there is a rule which stops all further processing of static files which are not found:

# Stop rewrite processing, if we are in the typo3/ directory or any other known directory
# NOTE: Add your additional local storages here
RewriteRule ^(?:typo3/|fileadmin/|typo3conf/|typo3temp/|uploads/|favicon\.ico) - [L]

But for this extension to work the request needs to be redirected to index.php and is then handled by a middleware. So make sure to add a rule like this before the blocking rule above:

# For EXT:deferred-image-processing
# If a processed image is not found, then redirect to index.php and let the middleware create one on the fly.
RewriteCond %{DOCUMENT_ROOT}/$1.$3 !-f
RewriteRule ^((fileadmin/_processed_|other-storage/_processed_)/.+)\.(gif|jpg|jpeg|png)$ %{ENV:CWD}index.php [L]


As the extension does everything itself automatically, there is not need for further documentation. If you feel, a documentation could be helpful, please contact me or open an issue with your question.


If you find a bug of want to improve the extension, you're free to fork it and provide a pull request with your changes. If you don't have the resources or knowledge, open an issue.


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