To resize images, open DJ-Catalog2 configuration and go to the Image processing tab.
Change the values (you can change the values globally and apply them differently for Category and Producer settings) and save your settings.
Go to the "Images Manager" tab and use one of the "Recreate thumbnails" buttons, depending on which image sizes you want to change.
Using reSmush.it
To compress images generated by DJ-Catalog2 - that is, thumbnails created right after adding new images and thumbnails dynamically created by modules - you need to click on the "Optimize images" button. The console will show you which images have already been processed and the reduction rate next to each.
