mv?

Honestly, just prefix or suffix the filename. I've been cataloging all my stuff like that for the past 30 years - including, for things like music, the track number, which the filesystem and every portable device under the sun will naturally sort and play in the correct order. Finding things can be done with regular filesystem tools like, well, find. And it will work exactly the same way in all OSes that have a concept of filesystem.

I like tagstudio. IIRC its for windows and Linux.

I know KDE's Dolphin has this built in, but I'm so afraid to use it because I imagine it'll take ages, and it wouldn't be recognized by anything else. 😬

https://github.com/TagStudioDev/TagStudio ? Still in alpha tho.

An other solution could be exiftool by Phil Harvey. Don't judge by how the website looks... It's probably the best and most complete tool to edit the metadata directly into your images (and way to much other formats xD).

Even though it's very well documented, exiftool is very complex and there's a lot to read and grasp before getting comfortable with it. There's always the forum if you have any question, but before asking the forum go through the FAQ (yes I know it's huge... But as starting point look at number 11) and search a similar question in the forum.

Here I found a topic that looks like what you're a looking for:

https://exiftool.org/forum/index.php?topic=7894.0

For images, you can use a photo library application like digikam and set tags on the files, which are saved both to a relational database and to the photo metadata inside the image file. For other file types I don't think there's anything standard.

I'd highly recommend hydrus network for that sort of thing. It's exactly what it's designed for, and is quite mature but still very actively developed.

https://github.com/hydrusnetwork/hydrus

I read that you're manually tagging them, so your process can be whatever you want to do.

For example, you can leave the images in their current folder structure and create a separate folder structure with symbolic links to an image, so in the character folder would be symbolic links to all the images like that. They also don't have to be unique, an image can be in multiple categories.

Alternatively you can use a spreadsheet and generate lists there.

Finally there are plenty of photo album applications that allow you to tag images.

To expand on my previous comment I dug a bit deeper the rabbit hole with exiftool to showcase how powerful meta tags are over conventional tags. I was curious how It would work and find an "universal" embedded tag system that works nearly on any software.

First thing first,from my personal research there are 4 important types of metadata fields:

• IPTC:keywords
• XMP:subject
• EXIF:XPkeywords (mostly for Windows)
• MacOS:MDItemUserTags (macos tagging system)

It's also possible to copy one over to the other. The most important ones are IPTC and XMP which are read by most image manager. XPkeywords and MDItemUserTags are OS specific to windows and macos respectively.

After some reading and fiddling around I used the following commands:

exiftool -IPTC:Keywords="Phil's Exif" Wallpapers/image_proxy3.jpg
exiftool -XMP:Subject+=one Wallpapers/image_proxy3.jpg
exiftool -XMP:Subject+=two Wallpapers/image_proxy3.jpg
exiftool -EXIF:XPKeywords="tagtest" Wallpapers/image_proxy3.jpg
exiftool -MacOS:MDItemUserTags+=tagging Wallpapers/image_proxy3.jpg

I spun up a lychee docker container to test if my tags are automatically recognized:

What does that mean ? Does are embedded meta tags that works with every software capable of reading the IPTC or XMP metadata. Those tags will follow your pictures rather than being bound to a specific software database. So your tags are portable and embedded into you files which is in my opinion a better long term solution.

There's probably way more to it and something that could be further explored is to export your metadata as .xmp file, add those tags into the OS (XPKeywords, MDItemUserTags), bash script to manipulates even further....

Hope it helps to give you a sneak peak on what exiftool is capable. I'm a noob with this tool but it already shines and shows it's power and capabilities with some basic commands.

Here are some resources if you want to give it a try and follow my trails:

https://exiftool.org/forum/index.php?topic=15344.0

https://exiftool.org/forum/index.php?topic=1752.0

https://exiftool.org/forum/index.php?topic=15802.0

https://exiftool.org/forum/index.php?topic=8591.0

https://exiftool.org/forum/index.php?topic=13102.0

https://exiftool.org/metafiles.html#EX15

https://www.picturesandstories.com/news/2014/4/21/tags-and-captions-how-to-label-your-digital-photos-using-metadata

image recognition with AI for categorization?