New fast DeBanding filter

[foxyshadis]

you want "strength" not strength. If it's unquoted it becomes a required argument.

[Jeremy Duncan]

"strength" creates a error.

[Soulhunter]

http://img100.imageshack.us/img100/2597/newsnap002541ro.gif

Bye

[hartford]

I tried this filter using defaults, ie, "gradfun2db()"

The result was a very screwed-up frame:

http://img56.imageshack.us/my.php?image=gradfun7hz.png

[hartford]

Nevermind, _I_ screwed-up; input must be YV12.

[adrianmak]

it is for playback ? instead of using in video encoding e.g. dvd -> xvid/divx

[Daodan]

I think the original purpose was for encoding (?). But since basically the crappy 12 bit color after encoding the bending will appear there again (a bit less though I would say). But it acts also as a spatial denoiser a bit so it can have some uses in the encoding process, but his great strength is at playback.

[Leak]

I think the original purpose was for encoding (?). But since basically the crappy 12 bit color after encoding the bending will appear there again
What 12 bit color are you talking about? YV12 uses a whopping 8 bit per channel...

np: New Order - Hey Now What You Doing (Waiting For The Sirens' Call)

[Soulhunter]

YV12 uses a whopping 8 bit per channel...
Dont you mean normal [non subsampled] YUV? >.>


Bye

[scharfis_brain]

every YUV colourspace supported by AVS has 8 bits/channel.

but due to subsampling the average amount of data is 12 bits/pixel. But this doesn't say anything about bits/channel!

[gatekeeper_007]

...from what I understand that this filter is being made only for viewing and not for processing.

I' searching for a filter that helps with 'banding' when compressing! (in YV12 mostly)...

any advice ?

:thanks:

[Manao]

Banding is best fought during post processing. Whatever method you'll try to use in preprocessing, it's more than likely that the effects will get lost during the compression, unless you're using a very high bitrate.

[Egh]

@ Manao: it still helps however. And, most important, this filter doesn't reallly destroy details in picture.

I use this filter for HD content which I transcode to avc. I can't see more banding added compared with filtered but not yet encoded video. Maybe AVC has less chance to create banding, dunno :)

[gatekeeper_007]

yes you're right..,
most of the time I get it when I'm compressing to much,
but sometimes I get banding even when all i/p/b-frames are 2 and 3 quant. with(H263/MPEG)... so I guess in that case it's not about the bitrate... and I try to found out why and how to fix this/if I can .

Thx 4 the reaply
and Keep up the good work
respect

[Hurricane Neddy]

yes you're right..,
but sometimes I get banding even when all i/p/b-frames are 2 and 3 quant. with(H263/MPEG)... so I guess in that case it's not about the bitrate...

Just cause a frame is a quant 2 or 3 doesn't mean it's high bitrate.

[gatekeeper_007]

Just cause a frame is a quant 2 or 3 doesn't mean it's high bitrate.

yes, I know that with differend settings and/or scripts you can mess a lot with the compressability of a clip, and you can get frames 2/3 quant which will need a low bitrate...
(but they wont look much like 2/3 quant)

...but when you're compressing at a 640x480 res. without using a denoiser, - costum matrix, or settings like 'lumi masking', trelis ... and others that can be helpfull with the compressabilyty , -without Bvop's or with but never higer than 1/1.0/1.0... etc. the bitate can't be so low...
to go higher with the bitate it wouldn't be smart as it won't be much of a compression anymore...
after all this way the clip is almost perfect:
-no blocks
-no artifacts
-no mosquito noise
-the only thing is the 'banding' I get (hoping to fix that to)

anyway...
I'm really sorry to post my question here, I didn't meen to mess much with the thread.
:thanks: 4 the replys

[mrcubehead]

I just wanted to say thanks, this solved a problem for me! :thanks:

[akupenguin]

Really, YV16/YV24 is the only way to truly remove visible banding in encodes. (If lavc could decode to YV24 and convert straight to RGB that would be awesome.)
That's not possible in inter-predicted codecs. No matter whether you meant higher colordepth or less chroma subsampling ("YV24" is ambiguous), any attempt to do that within the decoder will introduce encoder/decoder desync, thus adding way more artifacts than you save in reduced banding. OK, so you could decode B-frames with higher colordepth than the format specified, but that wouldn't really help if they're predicted from a banded P-frame.
The only way it will work is if the encoder and bitstream also use the higher colordepth, i.e. h264 hp.

[Comatose]

Two examples of gradfun2db in action (preprocessing, but it has a very nice effect when banding is this visible, even after encoding):

http://xs124.xs.to/xs124/08062/gradfun2db558.png

(this image is actually after a few scene changes from the last one)
http://xs124.xs.to/xs124/08062/gradfun2db2838.png

[Adub]

Here is a question, how do you deal with the color residue leftover after a debanding filter has been applied?

Sure, the hard edges have been removed, but often times there is still a soft band of color lingering in its wake.

This only happens on some sources I know, mainly any with strong banding, but I am wondering how to deal with those select few.

[foxyshadis]

Raise the strength, then add noise. That's about it.

[Adub]

So, say that I have gradfundb(1.4) and it removes the hardedges, but it leaves the color.

If I raise it to (1.5) or (1.6) and use AddGrain(), then that should take care of it? Wouldn't that hurt compressibility? Or is it negligible?

[foxyshadis]

Well, you might want to apply separately to luma and chroma.
l = gradfundb(1.4)
c = gradfundb(2.2).addgrainc(0.0,1.0)
mt_merge(l,c,c,y=2,chroma="copy second")

[Adub]

Cool. Thanks for that.

I was under the assumption that banding was a chroma artifact only. I guess to assume makes an Ass out of U and Me.

I will give that code a try and see how it goes.

[Undead Sega]

although i havent tried it, but this filter would work great to help hide decoding artifacts from Divx videos and as such to provide a much cleaner source which doesnt appear to have much compression in the video file, like MPEG 2 and lossless (to be prefered, as there isnt any:D).

[vaioslar]

Hello. I am trying to figure out what to do to get rid of banding (actually almost everybody in this thread)..

So I have this after encoding (Banding is mainly visible in the sky) : http://thumbnails5.imagebam.com/415/ba7e904141804.gif (http://www.imagebam.com/image/ba7e904141804/)http://thumbnails3.imagebam.com/415/2e38314141805.gif (http://www.imagebam.com/image/2e38314141805/)

What do you think I should try?

[rfmmars]

I simply can't see it, is your display the problem?

Richard

[vaioslar]

I simply can't see it, is your display the problem?

Richard

It is like some pixels are darker than others and these ones seem to be moving...i can upload a video sample..

[rfmmars]

Yes a clip that would help...........looking at your samples I see no banding that why I thought you may not have your monitor set at 32 bit resolution. Does this show on a DVD?

Richard

[vaioslar]

Yes a clip that would help...........looking at your samples I see no banding that why I thought you may not have your monitor set at 32 bit resolution. Does this show on a DVD?

Richard

I will now upload a sample. It is not actually a DVD. It is a BluRay

--->http://rapidshare.de/files/38916572/herritage_mono_lsf-muxed.rar.html

[burfadel]

Hello. I am trying to figure out what to do to get rid of banding (actually almost everybody in this thread)..

So I have this after encoding (Banding is mainly visible in the sky) : http://thumbnails5.imagebam.com/415/ba7e904141804.gif (http://www.imagebam.com/image/ba7e904141804/)http://thumbnails3.imagebam.com/415/2e38314141805.gif (http://www.imagebam.com/image/2e38314141805/)

What do you think I should try?

There's no banding that I can see. However, I can see slight borders of the macroblocks in the sky which is a different issue! If you have a CRT monitor you might be seeing a slight moire pattern than can happen sometimes.

[vaioslar]

There's no banding that I can see. However, I can see slight borders of the macroblocks in the sky which is a different issue! If you have a CRT monitor you might be seeing a slight moire pattern than can happen sometimes.

I don't use CRT monitor. I have a LCD-TFT 20''. It is ovious that something happens with the sky.. I supposed it was banding..I still believe it. If you use CoreAVC you might not see it that much... I don't know what exactly to do with that.

[rfmmars]

I ran your clip processed with HDRagc and only then could I see any blocking, still see no banding. The problem must be in your software/hardware driver, give us more detailes please.

http://img223.imageshack.us/img223/4199/cantseebandingyh9.th.png (http://img223.imageshack.us/my.php?image=cantseebandingyh9.png)

Richard
photorecall.net

[vaioslar]

I ran your clip processed with HDRagc and only then could I see any blocking, still see no banding. The problem must be in your software/hardware driver, give us more detailes please.

http://img223.imageshack.us/img223/4199/cantseebandingyh9.th.png (http://img223.imageshack.us/my.php?image=cantseebandingyh9.png)

Richard
photorecall.net

I have a BluRay and i am encoding it to mkv. After the encoding this think becomes visible in not only me. I am trying to find a filter that will remove as much is possible to.

http://thumbnails5.imagebam.com/419/a30fbd4180557.gif (http://www.imagebam.com/image/a30fbd4180557/)

[paparoachh]

hi ...
i have the same problem with vaiosLar ... and i cant deal with it .. can anyone help ? i post the biggest problem .. only on water and sky .. and not anytime ...
http://thumbnails5.imagebam.com/419/691e284182138.gif (http://www.imagebam.com/image/691e284182138) http://thumbnails5.imagebam.com/419/b9ec764182140.gif (http://www.imagebam.com/image/b9ec764182140)

what could i do .... ?

[Ranguvar]

Encoding causes banding. Sorry, it's a fact of life.

Running one of these filters on the video after encoding, while watching can help, but obviously that won't work for hardware players.

What codec are you using?

And as a note, I just see very slight banding and slight macroblocking... very slight. Watching this video at any normal frame rate, I'd be shocked if you can pinpoint those.

[paparoachh]

Ranguvar... its on encoding.. i am using ffdshow ... with kmplayer.. and VLC .. i can give you a sample...where you can see the problem ..the frames are 29.97 ...

[burfadel]

I can see very slight banding in the sunset pic, but still in the blue sky pic I can only see macroblocking, even when running brightness/contrast/gamma on it. In both cases they are very slight. LCD monitors are naturally limited in their capabilities particularly when it comes to colour ranges and producing 'black' black images, not to mention the response time of the monitor. I'd be much more concerned in my opinion of monitors with a response time of 5ms or more. I also hope that you're not sitting as close as 1 foot (around 30cm) from the screen to see the macroblock/banding issues!

[nautilus7]

@paparoachh, this isn't banding... or at least it's minimal. Can you post a source sceen as well? And provide us the bitrate your are encoding at.

[paparoachh]

lol no .. i am 50 cm away ..or ever 2 feet ...HD is for close things ..:P otherwise SD would be ok .. !i have an LCD 5ms ... 24" ..
nautilws..i cant post source stuff right now...i have to transfer it form my laptop ... bitrate is 4476 ... for the video ..

[nautilus7]

You're doing x264, right? Most probably the source has these issues, or your settings are very bad. But unless you post a source screen, we will speculating.

What/which is the source?

[paparoachh]

You're doing x264, right? Most probably the source has these issues, or your settings are very bad. But unless you post a source screen, we will speculating.

What/which is the source?

yeah 720p x264 ...
The World Natural Heritage-Europe I & Europe II 2007 Blu-ray 1080P AVC DD2.0

i dont think that my settings are very bad...because i encoded it once... and it was pretty nice..but in some points..like that ,i had a problem ...

[scharfis_brain]

I guess you guys are using cheapo LCDs.
The internal processing of these LCDs often causes banding which is not fixable.
I am using a 24" CRT (Sony FW-900) and it dosn't show any excessive banding.

[burfadel]

I agree with the above statement, especially since most monitors are only 700:1 contrast ratio. Even the '5000:1' monitors are really 1000:1. The full colour gamut monitors are easily 50 percent at least more expensive for the same thing. For instance, Samsung 226cw compared to the Samsung 226bw.

The 226bw is good enough that you probably won't have any problems despite it belonging to the budget LCD monitors, it was just an example!

[vaioslar]

Well, I've got Samsung 206 BW...This phenomenon is not only seen in my monitor but also when viewing the encode in the projector..

In addition screenshots do not show the problem that much

[paparoachh]

i have the LG L246WH ... so i dont think that my monitor has a problem...changing a few things in the avis, the situation now is a bit better ...but nothing special ...

[Soulhunter]

I cant see much banding either on this images!

But I have a CRTs as well... ;]


Bye

[scharfis_brain]

I guess some Cheapo LCDs are fooling their owners with excessive banding...

[Adub]

Does anyone have Manao's "optimized" build lying around? The download link in the first page is dead.

[*.mp4 guy]

I can see Banding in all of the images posted (accept the rescaled HDRagc images, they have different problems, some sort of odd horizontal stripes), without even looking at them fullscreen in mpc, I'm using a trinitron crt, btw; granted, its slight banding, and there is also blocking, but its still there. watching at full speed or not doesn't really impact how obvious banding is, since banding usually is worse on skies, and other objects that are often stationary. I can't even begin to understand why people are so quick to ignore issues like this, there is a problem, and even if its not a HUGE glaring flaw, its still there and sticking your head in the sand and blaming it on LCD's (which I will admit, often cause such problems, at least among cheaper models) doesn't help anyone.

AQ works quite well for reducing, or, at high bitrates, eliminating banding, search for VAQ, and get a build of X264 with version 0.48, or check out the new version 2.0, which is iirc is still being tested. If VAQ alone isn't enough, you can also add a cqm to the mix, many people report good results with the prestige matrix, though it can cause artifacts at times, Sharktooth and I also have cqms which may be able to help you. Beyond these suggestons, preporcessing in avisynth (usually mvtools denoising of some kind, followed by ttempsmooth then gradfun2db works very well) can also help reduce the amount of banding in a final encode. As a last resort, raising your video bitrate, always helps, though when dealing with banding, increasing your bitrate without doing anything else is surprisingly ineffective.

I realise that inexperienced people often come here and complain of problems that don't exist, or are a case of PEBKAC blown out of proportion, but i think this leads the more experienced members of the forum to discount real problems that newer members may report without as much thought as they would put into it if someone who has been here longer had the same problem.