[quickthrower2]

Can the real smear be undone using a filter?

[Daub]

Don’t think so. A filter can blur, and in theory can also unblur. But in practice, cannot.

Reminds me of this disturbing case…

https://www.minnpost.com/politics-policy/2007/11/you-can-swi...

[bcraven]

Deconvolution might be able to unblur it.

https://www.mathworks.com/help/images/deblurring-images-usin...