Sent: 2010-03-09 18:51:26 UTC (almost 2 years ago)

From: Jeff B

Image sharpening with "compressed sensing"

permalink

Hi,

I'll start by saying I am neither a GIMP developer nor do I have any
experience
with algorithmic image manipulation. However, as a GIMP user I *REALLY*
wanted
to make sure the GIMP development community is aware of the following
since many
of you *DO* have the talent needed to handle this.

It seems there is a new mathematical technique available which can be
used to
sharpen blurry or noisy images. From what I have just read it produces near
magical results. To quote from the article regarding the improvement in the
images: "It was as if you gave me the first three digits of a 10-digit bank
account number — and then I was able to guess the next seven."

I am also not a mathematician, but I can sort of understand how the
algorithm
works: It modifies the images repeatedly and on finer and finer scales
converging
always towards lower image complexity thus eliminating much blurriness
and noise.
In point of fact almost all real-life subjects have edges and other
structures.
The real world is mostly not blurred. This "compressed sensing"
algorithm somehow
implicitly "understands" (note the quotes) that blur and noise is not
what the
real world is about and it is able to supply missing data to correct
images from
the real world.

Here is a pointer to a recent article on the subject published in Wired
Magazine.
Please read it.

http://www.wired.com/magazine/2010/02/ff_algorithm/all/1

As GIMP user who looses a lot of images due to them being underexposed
or out of
focus, I'd *REALLY* love to see a "compressed sensing" image sharpener
plugin for
GIMP. I think many other GIMP users would like it a lot too.

Thanks for reading,
Jeff Barry
Acton, MA, USA.

_______________________________________________
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer

Sent: 2010-03-09 20:42:37 UTC (almost 2 years ago)

From: Bill Skaggs

Image sharpening with "compressed sensing"

permalink

You might wish to read the clarification at

http://nuit-blanche.blogspot.com/2010/03/why-compressed-sensing-is-not-csi.html

It explains how that Wired article is misleading, and why the technique is
probably not very useful for the sorts of situations that Gimp users
commonly encounter.

Regards,

-- Bill Skaggs

_______________________________________________
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer