Preview Generator - Gallery app only showing "thumbnails"


I recently installed the preview generator in my environment. I may misunderstood the app. What I thought it would be was a tool to create thumbnails off all your media on the nextcloud instance, so that the thumbnails are not generated on the fly when I view a folder with the app or via browser.

Thats why I set
‘preview_max_x’ => 256,
‘preview_max_y’ => 256,

When the previews were generated after that, I saw, that the gallery app uses the preview pictures as… previews. Not only as thumbnails.

Is there any way to configure nextcloud or the preview generator app to just generate thumbnails, but show the full quality pictures when clicked on them in the gallery???

Hi @Reudinger

With the the “preview_max” values you define the maximum size of the previews / thumbnails to be generated, regardless of whether they are created with the Previewgenerator App or on the fly, while you are viewing the images in the Gallery App. And because everything that is displayed in the Gallery App are actualy peviews / thumbnails, you only see the pictures with the defined maximum preview size, which In your case is 256 x 256 pixels.

Oh okay, so there is no way to use the previewgenerator to just generate thumbnails and open the full size picture when clicked on it?

yes and no. You cannot open the original image in the Photos app. But that’s completely unreleated to the Preview Generator app. The Photos app just dosen’t do that. It always shows a compressed preview of the original file. But if you remove the max_size preview parameters or set them to a significantly higher value, you can open a full size preview or at least a nearly full size preview. (I don’t know if there is a hardcoded max_size)

And of course you can still use the Preview Generator app, if you remove the max_preview setting or set it to a higher resolution. The Preview Generator will then also pre-generate the higher resolution previews, which means that when you open images in the Photos app, they will be displayed quicker too, just like the smaller thumbnails.

Disadvantage of using the Preview Gnerator app like this: The previews need more storage space. because the higher resolution previews are generatetd for every picture, also for those you may never look at in the app. But it’s still a lot less than the actual file size, depending on size and compression of the source material of course.