Regenerate thumbnails?


#1

How can I regenerate thumbnails in Omeka S after changing the resolution settings in the local.config.php file?

I also note that these settings are not visible in the admin GUI, unless I missed it.


#2

In Classic, that functionality is provided by a plugin, DerivativeImages. To my knowledge there’s not currently a version of that available for Omeka S as a module.

And yes, you’re correct that those settings currently are only available in the configuration file. We’re open to arguments for changing that, of course.


#3

Can I hack a quick module that just runs a function? Or trigger a run via calling a specific PHP page?


#4

The method that actually creates thumbnails for a file is in the Omeka\File\TempFile class, the method storeThumbnails. You’d have to setTempPath to the path to the file on the filesystem and setStorageId to the storage ID for the media record: both of these are stored in the Media table.


#5

I built a quick plugin for that: https://github.com/Daniel-KM/Omeka-S-module-DerivativeImages. Not yet tested a lot.


#6

The version on github is now the good one.


#7

I’d like to have that option to change the resolution settings, especially as the current medium and square ones are set to the same width. Also, being able to add a larger size than the default 800 could be helpful for themes that are using full-width presentation of images.


#8

You can already change the resolution settings for the thumbnails in config/local.config.php. What do you want to do beyond that?

This thread is about updating already-created thumbnails after those settings are changed.


#9

Sorry for hijacking the thread - I saw your comment about settings being only available in the config file, and you mentioned being open to arguments for changing that. I would request making it accessible in the UI, as it would be a useful option for site admins who may not have the ability to access the config file, and I believe Omeka classic has this functionality. Should I start a new thread for that?