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Old 17th September 2009, 08:27   #121  |  Link
leon1789
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Quote:
Originally Posted by thewebchat View Post
http://img136.imageshack.us/img136/1469/dongs.png

leon1789's method seems to produce the same results as the traditional GFMirror.
Hello,
I see two frames, with a problem in the top right corner of the second picture.

Can you explain a little bit more, please : where is the source? Which image is the result of which filter?
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Old 4th October 2009, 07:53   #122  |  Link
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Quote:
Originally Posted by leon1789 View Post
Hello,
for the same job, I propose this simpler code
Code:
Function GradFun2dbMod(clip c, float "strength")
{
strength = default( strength, 1.2 )
w = c.width+32
h = c.height+32
c = c.PointResize(w,h,-16,-16,w,h)
c = c.GradFun2db(strength)
return c.Crop(16,16,-16,-16)
}
What do you think about it ? (specially in the corners of the picture)
Please, change the name of your function because this name is already used here:

http://forum.doom9.org/showthread.php?t=144537

Thanks


edit: On top of that, this pointresize method is already in my GF2mod...

If you want the same output as your mod:
Code:
GradFun2DBmod(str=0,mask=false)
str=0, disable adaptative grain
mask=false, disable selective debanding

Last edited by LaTo; 4th October 2009 at 08:29.
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Old 4th October 2009, 12:18   #123  |  Link
leon1789
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Lato, you're absolutely right (for name and output).

So, my proposition is obsolete...

Last edited by leon1789; 4th October 2009 at 12:26.
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Old 6th September 2012, 17:06   #124  |  Link
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I tried to download today, and the link in the first post was bad. In fact, the whole http://kosmos.kawaii-shoujo.net/ subdomain appears to be down.

Anyone have an alternate location to download the .dll from?
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Old 6th September 2012, 17:34   #125  |  Link
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Here you go: http://chaosking.de/wp-content/uploa...2006-05-05).7z

x64 version : http://chaosking.de/avisynth-filter?q=gradfun
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Search and denoise

Last edited by ChaosKing; 6th September 2012 at 17:36.
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Old 6th September 2012, 18:05   #126  |  Link
sneaker_ger
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You might also want to take a look at these:
flash3kyuu_deband
GradFun3
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Old 6th September 2012, 21:19   #127  |  Link
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Quote:
Originally Posted by sneaker_ger View Post
You might also want to take a look at these:
flash3kyuu_deband
GradFun3
Thanks.

I'm trying to deal with relatively subtle banding that shows up in dark live-action underwater shots (frames of just blacks and dark blues). I've had reasonable success with GradFun2DBmod.v1.5 (which needed this plugin to work.

Are there other filters that are recommended these days? I can certainly imagine something faster; It's taking 8x real time on my 12-core monster box (using very few cores).
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Old 6th September 2012, 21:38   #128  |  Link
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Flash3kyuu is pretty fast, should be faster than real-time. For specific tips for your source you should ask in the respective threads, as I cannot provide those.
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Old 7th September 2012, 00:17   #129  |  Link
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Flash3kyuu is very good. I use it for dithering 10 to 8bit (with use of tweaked for 10bit support ffms2: http://forum.doom9.org/showthread.ph...72#post1585372)- it should be way faster than RT on 12 core machine. Very powerful combination
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Old 15th January 2013, 15:24   #130  |  Link
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Hi,

I have a question : should I denoise after using gradfun or before ? Also, is it suitable to denoise a frame that had been debanged ?
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Old 15th January 2013, 16:49   #131  |  Link
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Quote:
Originally Posted by sirt View Post
Hi,

I have a question : should I denoise after using gradfun or before ? Also, is it suitable to denoise a frame that had been debanged ?
Usually debanding / dithering filters go last.

Debanding /dithering filters essentially add "noise"

If you apply denoise afterwards, it impairs the debanding effect
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Old 15th January 2013, 16:57   #132  |  Link
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Denoising introduces banding or is very prone to, I think that answers it all.
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Old 15th January 2013, 17:28   #133  |  Link
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Thanks for those answers. Another thing, could you clarify the difference between debanding and dithering ?
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Old 15th January 2013, 17:40   #134  |  Link
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Thanks for those answers. Another thing, could you clarify the difference between debanding and dithering ?
In this context (gradfun2dbmod) they mean the same thing

In the more general sense, "debanding" can denote several different approaches to removing "banding" (and there are different type of "banding"), one method of "debanding" is dithering

http://en.wikipedia.org/wiki/Dither#Digital_photography_and_image_processing

There are different types of dithering, different algorithms. Basically they all add noise that "covers up" banding. Noise impairs compression - it requires more bitrate to encode. Ordered dithering techniques have less fluctuations, thus require less bitrate. And example in avisynth of ordered dithering is gradfun3
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Old 15th January 2013, 19:13   #135  |  Link
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Debanding is smoothing the gradients to make them uniform, like a blur filter does.

Dithering is downgrading de color palette (from 16 to 8 bit for example) while using patterns to make for the dinamic range loss without too much percieved quality loss, like gif does.

Then in the dithering process sometimes noise is added to give a more natural look.
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Old 15th January 2013, 19:25   #136  |  Link
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Thanks for those detailed answers. Then, I've given a try to GradFun2DB and its variants but they are intended to debang as from I've read from the AVS External Filters page. But, in thise case, what would be a filter to dither assuming it is slightly something different according to your previous explanations ?
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Old 15th January 2013, 19:39   #137  |  Link
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Around here we usually we only speak of dithering in the sense of a method of reducing the bit-depth - which is more in line with what Are_ said than with poisondeathray's post.

Filters like gradfun2db, gradfun3 and flask3kyuudeband do debanding in high bit-depth (i.e. try to create smooth gradients in an already banded source with e.g. 16 bit output) and as a last step do dithering to a lower bit-depth (e.g. 8 or 10 bit). Dithering is to be seen as opposed to simple rounding, which would re-introduce a lot of banding. Poisondeathray's wiki link explains it. Image 1 of the cat is the original high bit-depth image and image 2 would be how the lower bit-depth image would look if we simply rounded down. Image 3 is how the bit-depth reduction looks with dithering.

As poisondeathray said, we have an additional obstacle to overcome, as random noise is extremely hard to compress. If you use Floyd-Steinberg dithering the AviSynth preview might look very good, but after encoding to low bitrate 8 bit h.264 the banding will have re-appeared or originally not existing banding will have been introduced. Methods to limit this effect are:
- switch to 10 bit H.264
- use ordered dithering (gradfun3 or the appropriate parameter if f3kdb)
- increase bitrate (a lot)

Last edited by sneaker_ger; 15th January 2013 at 19:46.
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