Allow loading larger preview or full-sized images in image viewer

[profi248]

I have major problems with performance of image folders (external storage, on spinny drive). Loading thumbnails takes a lot of time or even, when there's a lot of pictures (>1000) in the folder, it completely overwhelms the CPU and RAM, rendering previews almost unusable. To improve this situation, I turned down preview size significantly and loading is a lot faster and actually usable now. The problem is that when you open that image, just the tiny thumbnail loads (and takes a long time to load as well, even though it's already generated).

I don't see a reason not to add an option to enable more tiers of thumbnails, with the larger one only being generated on demand, when the photo is opened. Or alternatively, a simple solution, just serving full-sized picture, as bandwidth is (at least for me), not a big concern on a computer.

Ideally, I would imagine small thumbnails generating in the background automatically, with larger previews generating as user opens the photos, which would be ideal in terms of speed as the server won't be overwhelmed by so many thumbnail requests, and disk space trade-off is small.

I know about https://github.com/rullzer/previewgenerator, but it's not a great solution as those large previews take up a ton of disk space, for nothing. And it didn't work for me, but that's a different issue. File loading is slow in general, at least in external storages, which is the only storage that fits my needs.

I am aware that this has been discussed already (#1968), but this issue is very old and without much interest.

[SimplyCorbett]

a simple solution, just serving full-sized picture

I don't understand why this isn't implemented by default.

[edenhaus]

A long time ago this feature was already discussed (nextcloud/gallery#38).
In my opinion option 2 (button on the preview to get the full sized image) would be perfectly.
The most of the time the preview image is enough and the few times, where you want for example to zoom in, you can click and wait for the full sized image.

[darmbrust]

I also, cannot fathom why none of the current image viewers I have tried have a button to show me the original photo. There is download, but that takes me to a file dialog. I don't want a file dialog. I just want the original, high quality photo in my browser. Why does this seem like a foreign concept to all of the nextcloud photo viewers? Gallery doesn't do it, the new (uesless) photos doesn't do it, the file viewer doesn't do it. For me, its the entire point of using nextcloud, to keep my photos handy, and yet, I can't view them worth a darn in any photo viewer. None of the slideshows even have a full screen option. I really don't understand the lack of these basic features in every single photo app.

[SimplyCorbett]

cc @skjnldsv

Is the ability to direct download a image when going through the slideshow viewer or the photos app an overlooked feature or is it not possible to implement in nextcloud for some reason?

Have to agree with @darmbrust that browsing thousands of images over the slideshow or photos app and then having to hunt them down in the file listing or share them for a direct download link is painful.

Why isn't there a direct download option?

[skjnldsv]

Is the ability to direct download a image when going through the slideshow viewer or the photos app an overlooked feature or is it not possible to implement in nextcloud for some reason?

Because we need a proper fileActions API so we can implement the file actions into viewer. Hardcoding actions is something I don't want to do.

a simple solution, just serving full-sized picture

I don't understand why this isn't implemented by default.

Because downloading a 22MB jpeg makes no sense when you want to preview a picture.

[skjnldsv]

the new (uesless) photos doesn't do it,

Please refrain yourself from posting comments like those in the future or think twice about phrasing so we actually get the will to read and help you. Thank you.

[SimplyCorbett]

Because we need a proper fileActions API so we can implement the file actions into viewer. Hardcoding actions is something I don't want to do.

Thanks! So it is a technical issue. It's not a big deal then. I just wish it was easier to direct download images on those applications.

Well, you're not wrong about the 22MB JPEG. But I think it's a waste to generate preview images on large albums if the nextcloud instance is on a LAN setup with no bandwidth limitation. But that's personal preference. Thumbnails would still have to be generated regardless.

Appreciate the response! 👍

[darmbrust]

Is the ability to direct download a image when going through the slideshow viewer or the photos app an overlooked feature or is it not possible to implement in nextcloud for some reason?

Because we need a proper fileActions API so we can implement the file actions into viewer. Hardcoding actions is something I don't want to do.

a simple solution, just serving full-sized picture

I don't understand why this isn't implemented by default.

Because downloading a 22MB jpeg makes no sense when you want to preview a picture.

I didn't say I was trying to preview a picture. I said I'm trying to view the picture. Your assumption that it makes "no sense" is rather flawed, and based on a use case that you assume, which isn't true for my deployment.

My nextcloud server is sitting 10' from the computer I'm browsing on, on a gig network. I have a 4K monitor hooked up to this computer, and, in any photo viewer currently available in nextcloud, I can't get anywhere near having a halfway decent photo viewing experience. In this deployment, the server is wasting resources generating midsize thumbnails I don't want, and refusing to give me an option to just view the file. The only thing I want from a photo viewer in my deplyment is small thumbnails for the folder view, and the ability to actually look at the photos in their proper resolution.

One would think those would be requirements 1 and 2 of a photo viewing app...

Quite honestly, I think that the entire point of nextcloud - self hosting content - should be more along the lines of making the assumption that you ARE on a close, fast network, and bandwidth is far cheaper than bending over backwards to try to generate the smallest, least objectionable copy of the photo.

Maybe you start to make those assumptions if the client is mobile, or at least least the administrator choose the behavior.

[jospoortvliet]

Quite honestly, I think that the entire point of nextcloud - self hosting content - should be more along the lines of making the assumption that you ARE on a close, fast network, and bandwidth is far cheaper than bending over backwards to try to generate the smallest, least objectionable copy of the photo.

You already mention mobile... And I share my photos with family, so the slow upload I have as private user is a huge bottleneck. Google and such have way stronger bandwidth than most private users - and thus I'd rather argue the absolute opposite of you: Nextcloud should be MORE frugal with bandwidth as the upload speeds of most home networks is tiny compared to data center solutions.

[skjnldsv]

Maybe you start to make those assumptions if the client is mobile, or at least least the administrator choose the behavior.

We need to cover all use cases.
Having on-demand preview size of data is the best take we can do for this use case.
If we start to say yes to every custom config switch we're receiving a request for, this is what our software will looks like at the end of the year. We won't do that.

[darmbrust]

Quite honestly, I think that the entire point of nextcloud - self hosting content - should be more along the lines of making the assumption that you ARE on a close, fast network, and bandwidth is far cheaper than bending over backwards to try to generate the smallest, least objectionable copy of the photo.

You already mention mobile... And I share my photos with family, so the slow upload I have as private user is a huge bottleneck. Google and such have way stronger bandwidth than most private users - and thus I'd rather argue the absolute opposite of you: Nextcloud should be MORE frugal with bandwidth as the upload speeds of most home networks is tiny compared to data center solutions.

Like I said, my server is 10' from my computer I'm viewing on. My mobile phone already uploads the full size images to the server. And its configured to only upload on wifi, when I'm home.

The server just won't let me have them back (easily).

I'm not arguing there isn't more than one use case, but this is exactly why the administrator should be able to configure the server for THEIR deployment.

[skjnldsv]

I'm not arguing there isn't more than one use case, but this is exactly why the administrator should be able to configure the server for THEIR deployment.

Feel free to edit Nextcloud's code and make it fit your need. We cannot supports everyone's setup.
Sorry!