A few days ago I became aware of the program Upscaler. This is, “a free, open source app that leverages the power of artificial intelligence to upscale image quality.” I tried it out on a fuzzy manuscript image from MS Kathmandu NAK 1-1079, and I think the result is extremely promising.
You may think that you can get this kind of result just by upping the contrast setting on your viewer. But what Upscaler does to the image becomes more apparent at greater magnifications:
The processing is quite slow, but highly worthwhile on a folio-by-folio basis if one is reading carefully. The processed image gives you a sense of the scribe’s actual strokes.