Well, imho AI upscaling is the way to go here in general. And turning it into a vector grahphics afterwards. Inkscape is capable of that step. And then you can correct it to your needs. What will not work is to turn crap into gold. The better the input image the better the output. And when you really have just a washy…
Maybe scale it even more down to get a better result. When you feed in a washy image then it will try to upscale this washy look ... there's a plethora of traditional computer vision techniques that will do the job Not this job, unfortunately. Traditional methods will not fill in fine details like hairs or surface…
Like some random phone taken picture of a sign, low res and blurry to something ready to turn in vectors ? I tried some Ai upscalers , Ai image generators , chat gpt . Upscalers are useless until you have already nice photo . Generators do something fancy and never what you actually need . I know Photoshop has some font…