Batch upscaling and compression script.

Upscaler is realesrgan-ncnn-vulkan-v0.2.0-ubuntu, you can get it from here.

• Make upscale.sh runnable from anywhere. An alias can solve this?
• The upscaler call in the script needs to then run from anywhere.
• Fix not being able to run if a folder has spaces in it. So escape whitespace and other characters? Maybe try and find a way to convert imported paths to absolute ones. This should fix spaces in file names aswell.
• If you just say upscale 1, it'll create a folder 1 and an Upscaled folder in it. Make a check to see if "1" actually exists, if it doesn't, don't do anything.
• Make a post on reddit about the ffmpeg issue.
• Think about moving the mkdir line up before the loop, so that it creates the folder for every upscale - this is useful for qimgv's single image upscale.
• Think about moving the mv line up into the loop too, so that it moves into the folder on every single upscale, so that it doesn't clutter shit up.
• Fix the qimgv AVIF script in ~/scripts/.
• Make this script executable from qimgv.
• Add image pixel count comparison in order to do AVIF or WEBP.
• Add flag to keep original upscaled image.
• Add more models, for instance digital art ones, see what Upscayl uses.
• Think of a way to constantly show the full progress bar when upscaling a folder. For instance, look up how many images are in the folder, and count how many have been upscaled, then show the progress bar based on that after every upscale.
• Upgrade to libaom 3.6.1 to fix AVIF issue, and then remove the pixel count check. (package libaom, still not updated in Fedora's repos.)

Clone the repo, and have ffmpeg and imagemagick installed.
I also suggest making a shell alias for the script to the folder you've cloned, so you can run it from anywhere.

alias upscale="~/Desktop/upscaler/upscale.sh" # For example

The upscaler uses a dedicated Vulkan-supported GPU to do upscaling.

./upscale.sh {file or folder you want to upscale} {--keep to keep original upscaled image}

You can suspend the process with Ctrl + z and resume it with fg.
You can stop the process with Ctrl + c.
Upscaling a folder will not upscale folders inside that folder, only the content, it's non-recursive.
Upscaling a file in a folder that already has the Upscaled folder will place the upscaled file in that folder.

As the upscaler is based on NCNN, you need .param and .bin files to use it.

Here are the models I most commonly use :

• UltraMix Balanced - Download from Upscayl's git repository, as I couldn't find it anywhere else.
• 4x UltraSharp - Download from The Model Database.
• UniScaleV2 - Download from The Model Database.

Place the downloaded models (.param and .bin files) in the models/ folder.

Using ffmpeg to convert to AVIF is not working for images that have more than ~35 million pixels for some reason.
I've tried various online converters and they worked.
From my testing the upscaled images weren't corrupt, as they're all generated the same way via the same upscaler, so it has to be ffmpeg.
I've also considered that it might be the file size, that's not it, I've tried it on some images that are ~80MB and it worked.
I've thought the ffmpeg parameters might be the issue, that's not it either.
I've thought it was the lack of RAM, but that's not it either.
The final test was resolution, and that seems to be it.
Here's the testing I've done.

• 5200x6496 works, 5600x6996 doesn't.
• 5300x6496 works, 5400x6744 doesn't.
• 5320x6644 works (35346080 pixels), 5360x6696 (35890560 pixels) doesn't.
• It's not the width or height specifically, 703x6694 works, and 5360x784 works. It's the number of pixels.
• 5360x6623 (35499280 pixels) does work, 5359x6666 (35729760 pixels) doesn't work.

Based on this I can make a cutoff to not do AVIF if the number of pixels is over 35499300.
So, for upscaled images that are larger than that, WEBP compression is used, the second best option, and that one works like expected.

After posting questions and doing some research, it seems like AV1 was never meant to be used for video over 8K, which this technically is.
Furthermore, there's a new version of libaom, 3.6.1, that actually fixes this exact issue, and allows you to compress video in higher resolutions.
See more here.
And here.