Auto-Resize Images Server-side

Installation

Requires ImageMagick and the PHP exec() function to call it.

Copy the extension to phpBB3/ext/ftc2/autoresize

Go to "ACP" > "Customise" > "Extensions" and enable the "Auto-Resize Images Server-side" extension.

You may need to tweak the following settings to allow uploading larger files or enable exec():

"ACP" > "General" > "Board configuration" > "Attachment settings":

• set Maximum file size to a large value (or 0)
• set Maximum image dimensions to 0

php.ini for the PHP installation used by your web server (look at your phpinfo() page or go to "ACP" > "System" > "General Tasks" > "PHP information"):

• increase post_max_size
• increase upload_max_filesize
• look at disable_functions and remove exec if it's there

If you're getting an HTTP error error popup when uploading large files, look in your browser's console. If you see plupload triggering 413 (Request Entity Too Large), then try configuring your web server to allow a larger client request body.

Description

Automatically resize (shrink) image attachments server-side upon upload.

Hooks to the core.modify_uploaded_file PHP event.

Note that phpBB supports client-side image resizing via plupload, a feature that should be better advertised... You can use this feature by specifying Maximum image dimensions in "ACP" > "General" > "Board configuration" > "Attachment settings".

However, the output quality is not that good, especially over large dimensional changes.

Resizing server-side with ImageMagick produces significantly better results (and smaller filesize in my testing) due to superior resize algorithm at the expense of server load.

If image quality is important to you and your server can handle it, or if you don't have people constantly uploading files, then this might be an attractive solution.

Example:

phpBB built-in resizing (plupload):

ImageMagick resizing with this extension with default -resize parameters:

The second image has a slightly smaller filesize.

Settings

From the ACP, you can trigger resizing based on uploads exceeding max filesize, max dimensions (width,height), or either one.

Regardless of how resizing is triggered, the image will be shrunk to not exceed specified max dimensions. Shrunk image is not guaranteed to be smaller than the max filesize.

You may specify ImageMagick parameters if you wish as well.

You must specify the path to ImageMagick. The mogrify binary must be available there.

This extension also includes a feature to log debug messages to a text file.

Changelog

v1.0.5 (06-05-2019)

• fixed deprecated license string

v1.0.4 (05-31-2019)

• brings support for phpBB v3.2.4 and above. Tested with phpBB v3.2.7.
• adds -auto-orient to the default ImageMagick parameters to fix rotation issues on some uploaded images

License

GPLv2