you can’t really “increase” quality, but you can get a higher res version or find one.

use this to find the highest res url, there’s also a firefox addon https://qsniyg.github.io/maxurl/

using tineye/yandex/google reverse image search is also helpful

Something like this?

https://i.pinimg.com/originals/de/83/4e/de834eb42e0b2f38a62c64e9b8d9f961.jpg

There is no way to add information without making it up. You can let AI make an educated guess to add information or you can add some pixels in yourself.

If you’re referring to downloading random pictures from the internet, you can do a reverse image search and find higher quality versions of the image if they exist on the internet.

Seems like you can’t download a image without getting it on a terrible quality anymore.

Where are you downloading from, and what?
Images are like any other content. High quality images are not free to make or host, so they might not be free to get either.

Having you tried telling your computer to “enhance”?

That always works on TV.

Dunno how much “AI” is in Waifu2X but that’s a tool I like to use for a quality upscale.

Do things other than these images you’re downloading also look any different? Text on websites sharper or more blurry?

Do old downloads still look the same to you, or have these somehow degraded in quality when you weren’t looking? Look closely.

Thus the lateral thinking answer: Check your screens and your eyesight. One or more of these may have a defect. Or an improvement for that matter. New glasses?

When pictures get compressed, the data is lost. It’s not hidden - it’s gone forever.

When you “increase the quality” with a tool like this, you’re not recovering lost data - you’re making up new data to fill in the gaps. It takes an intelligent system to figure out what should probably be there and then add it convincingly.

I don’t think you can pull that off without AI.

It really depends on what your sources are.

For instance, the ESA has many options for most of their pictures, one of them being a 122.4mb TIFF. Then there will be all the aggregator sites that host the same image at lower quality…

As for increasing the quality; it’s really difficult to do. IIRC there was a group of people that hand edited each and every frame of the original Star Wars trilogy from VHS quality to 4k. It took years and they almost ran out of money before finishing the Empire Strikes Back. As much as I hate how AI is being shoved down everyone’s throats these days, this is one of those things that it is/would be good at (when applied properly) and was actually meant for; trawling through massive amounts of data and making connections.