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-   -   Encoding: Interesting Picture Noise Filter (http://www.digitalfaq.com/archives/encode/2515-encoding-interesting-picture.html)

jorel 02-07-2003 01:01 AM

Encoding: Interesting Picture Noise Filter
 
:wink:
seems very cool,read about:
http://virtualdub.everwicked.com/ind...=ST&f=7&t=1604
and the samples are "delicious" :lol:
:roll:
i read about but can't find "where" is this filter to download.
if someone get,please put the link.
thanks.

editing:
found home page,
http://www.neatimage.com/howto.html

"Licence:
The Demo edition of Neat Image is distributed
as freeware for non-commercial use.
See the documentation supplied with the software for more details. "
:wink:

GFR 02-07-2003 05:27 AM

Uai!

Nice filter. It's the same approach used to clean hiss and background noise in audio files: you take a "noise only" sample, get some statistics and use it to decide what's noise and what's signal. For example, see the "noise reduction" filter in Cool Edit. It looks like it makes a nice image denoiser too.

I think I could write a filter like that for avisynth, if I could program in C++ :cry:

Audio processing software can be a good source of inspiration for video filters...

jorel 02-07-2003 06:47 AM

Quote:

Originally Posted by GFR
Uai!

Nice filter. It's the same approach used to clean hiss and background noise in audio files: you take a "noise only" sample, get some statistics and use it to decide what's noise and what's signal. For example, see the "noise reduction" filter in Cool Edit. It looks like it makes a nice image denoiser too.

I think I could write a filter like that for avisynth, if I could program in C++ :cry:

Audio processing software can be a good source of inspiration for video filters...

"Uai!" :lol:

kwag 02-07-2003 08:31 AM

Wish we could use that on video :)

GFR 02-07-2003 10:49 AM

You can find the Audio algorythms for this technique (and sources!) here:

http://gwc.sourceforge.net/

http://gwc.sourceforge.net/gwc_science/

http://www.ind.rwth-aachen.de/resear...reduction.html

http://www-sigproc.eng.cam.ac.uk/~pj...rch/noise.html

If we extend it to 2-D, and implement it as an avisynth...

kwag 02-07-2003 11:17 AM

Neatimage is very good, but it's SLOOOOoOoOoOoWWW :lol:

-kwag

GFR 02-07-2003 12:36 PM

Quote:

Originally Posted by kwag
Neatimage is very good, but it's SLOOOOoOoOoOoWWW :lol:

-kwag

If you look at the algos above you'll understand why: you first select a block of "noise only" and do a FFT of it. Ok, that's once for each image and that's fast.

Then, you select a block of the image, FFT it, use the noise FFT to modify it, and do a IFFT. You have to perform a FFT, the denoising and a IFFT for each block, and that's sloooow.

But, when you select a new block, it's not an adjacent block like in mpeg coding, it's an overlapping block!!!! So you've got a total number of blocks that's much greater than the image size / block size, and that's what makes it SLOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOW.

jorel 02-07-2003 04:52 PM

:cry:

yeah,SLOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOW
.................................................. ...............................
...and boring! :roll:

kwag 02-07-2003 05:41 PM

I've been playing with this for a while now, and even though it's a very slow process, the results are really amazing 8O
I've converted several pictures from my old Sony Mavica Floppy Disk camera, and it really cleans them up. It removes a lot of the grain and smoothens the picture without loosing details. You have to be careful when you select a new block :!: Just select enough so that it displays "high frequency" and not "high frequency+medium", etc. If you do, then a lot of detail is lost, and people look like ghosts :lol:

-kwag

vhelp 02-07-2003 07:42 PM

Hello everyone. Wow !!

I've just D/L'ed those two pics, and I almost don't believe it.
I ran them through my picSwitch app and could see the difference in the
amount of detail between them when switching pics. It's amazing in the
detail, how you can things you don't normally see when just viewing two
pics at the same time, or using a clunky app like a brower to switch between
them. (I've updated the version to v1.1.2) Anyways..

The pic that is noisy reminds me of VHS, and how its grainy/noisy. Next,
it reminds of flaXen's VHS filter v1.0 :wink:

If that kind of detail could be acheived via VHS source, I'd be in love !!

But, I couldn't help noticing the detail.

-vhelp


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