Sunday, October 6, 2013

Improve Image Quality by Upscaling?

Is it possible to improve image resolution or clarity by upscaling?

Conventional Wisdom says that it can't be done.
You can't add information which isn't there in the original!

Or can you?
Here is an example of where upscaling does appear to improve image clarity.
Could this be due to the jpg algorithm which generated the source image?
that jpeg actually is to encode info at a higher resolution than is presented?

1 comment:

inachos said...

I know I am five years late, but here's an answer: Pixels are terrible at representing slanted lines. If an image has a lot of curved/diagonal lines, upscaling will make everything blurry, but these lines will be more faithful.

This picture has a lot of rounded lines in there, and these will all be more accurately represented after upscaling. Try the same on something with mostly vertical/horizontal lines, and the result will be much poorer.

Basically, this is just spatial anti-aliasing doing its magic.