04-21-2019, 11:28 AM
(04-21-2019, 09:35 AM)Ofnuts Wrote: As usual, Garbage In, Garbage out.
How true! So, on scaling from .jpg, I always try first of all to reduce garbage--usually accomplished by blurring. Yes, that uses to improve results, at least blurring preserving edges, if possible, to get rid of compression artifacts. Those, if present, will get scaled and sharpened, and thus magnified as a rule.
I usually use plugin simply-bilateral, from the gimp repository, but no doubt there are alternatives...
After that, of course, I would scale and sharpen, in that order--or, for small images, where the default sharpen filter can be too strong (too thick black lines) instead:
- duplicate layer
- upper copy -> mode: soft light -> filter: high pass -> if needed, play further with mode and/or transparency.
Not perfect, but I hope it helps...
