dfttest - 2D/3D frequency domain denoiser.

[tritical]

@nonsens112
Your suggestions seem fine to me. Making the temporal radius unequal going backwards/forwards is rather difficult taking into account windowing. For now I'll stick with only the first two items . No guarantees on when it will get done though.

@all
I discovered a bug in dfttest's window normalization under the following scenerios:

tbsize>1, tmode=0
consequence is a rectangular temporal window regardless of what twin is set to

sbsize>1, smode=0
consequence is a rectangular spatial window regardless of what swin is set to

In the smode=tmode=0 case you got rectangular for both temporal/spatial.

I should have a fix up later tonight.

[nonsens112]

Making the temporal radius unequal going backwards/forwards is rather difficult taking into account windowing.

I wonder what's difficult - current implementation limitations, possible quality issues (3D-ringing or like that) or smth else? or a mixture of?)))

I'll stick with only the first two items . No guarantees on when it will get done though.

that's great anyways hope the features will be useful to many people.

[Keiyakusha]

Hi. Please can someone tell me what options of this filter actually do? I mean when I need to adjust them? I have read the documentation but I don't understand it.

Y,U,V - If true, the corresponding plane is processed. Otherwise, it is copied through to the output image as is. default: true,true,true

So I need to add u=false,v=false parameters if I want to process only luma?

ftype - Controls the filter type. default: 0 - generalized wiener filter; mult = max((psd-sigma)/psd,0)^f0beta)

I guess I better leave it at default?

sigma,sigma2 - Value of sigma and sigma2 (used as described in ftype parameter description)

"ftype parameter description"- this is that formula? I don't understand what it means. This option is something like sigma in FFT3Dfilter?

pmin,pmax - Used as described in the ftype parameter description.

Again, have no idea what it means and when I should adjust it.

tmode - Sets the mode for temporal operation

Default is good most of the time?

swin,twin - Sets the type of analysis/synthesis window to be used for spatial (swin) and temporal (twin) processing.

Should I adjust this parameters or defaults is good?

Sorry for dumb questions. Please give me a link if I can read about it somewhere else.

[Nightshiver]

the sigma's are the strength of the filter. The high you set it, the stronger it denoises. For just about every use you will have for this filter, you will not need to alter anything, save the sigma.

[tritical]

So I need to add u=false,v=false parameters if I want to process only luma?

yep.

For general denoising, only ftype=0 and ftype=1 are useful. ftype=0 actually becomes ftype=1 as the value for f0beta approaches 0. pmin/pmax/sigma2 are only used in ftype>1 so you don't need to worry about those. ftype>1 is really only useful if you plan to use the 'sfile' parameter to specify sigma values for specific fft coefficients... in which case you can accomplish all sorts of frequency domain manipulations.

As for tmode, I would always use 0. 1 is faster (its the same idea as smode=0 vs smode=1 in the spatial domain), but in the temporal domain it causes artifacts. swin/twin you could play around with. The defaults are what I've found to work best in most cases. They also worked best in the ssim/psnr tests I've done. See http://en.wikipedia.org/wiki/Window_function for some information on the different windows.

If you are trying to remove noise that isn't white, the nfile parameter (which allows you to specify blocks containing only noise, from which dfttest estimates the noise power spectrum) can be very useful.

[Keiyakusha]

Oh, big thanks for the explanation!

[rkalwaitis]

Tritical,

I am trying to use the nfile option and I receive an error that states unable to open nfile. Is there something special I should be doing. Perhaps a little example. Thanks. Also is there a way to make the nfile do each frame, remember the results for use by the denoiser, instead of working on an average?

Thanks

[tritical]

I am trying to use the nfile option and I receive an error that states unable to open nfile. Is there something special I should be doing. Perhaps a little example.

What is your script? What is in your nfile? When I use the nfile option it works fine... so I need a little more information about your problem.

Also is there a way to make the nfile do each frame, remember the results for use by the denoiser, instead of working on an average?

You actually have a clip where the noise power spectrum is changing on every frame, and the same position on the image is always flat with just noise? Or do you intend to manually specify locations for every frame?

[rkalwaitis]

Tritical I have no real script for use of the option. I was trying to make it work via your read file. I thought that the nfile took a sample of a frame and used that to compute denoising. I was just wondering if it could do it frame by frame.

Thanks K

[onesloth]

Originally Posted by rkalwaitis

I thought that the nfile took a sample of a frame and used that to compute denoising. I was just wondering if it could do it frame by frame.

Somebody correct me if I'm wrong but my understanding is that one uses nfile by defining an area of one frame from the clip where there is nothing but noise (e.g. a flat color background). The analysis of that noise area is used to tweak the denoising parameters for the whole clip *not* just the frame in which the area is defined.

I think Tritical's point is that he would be really surprised if the noise in your clip changed significantly from frame to frame (thus requiring a new noise sample) and that it would likely be impossible for you to find a flat noise-only area in *every* frame that would be suitable for defining the noise.

[rkalwaitis]

This makes sense to me. Thanks for an explanation. Thanks Tritical for the great denoiser.

[lansing]

my script was this:

MPEG2Source("sample.d2v", info=3)
colormatrix(hints=true)

dfttest()

And I'm seeing ghosting in some dark area. Noticed the blue coat.

Original:


dfttest:



I've uploaded a sample here.

[tritical]

Have you tried reducing tbsize and/or sigma, or running dfttest on a motion compensated version of the video? dfttest is definitely not immune to ghosting when using 3d filtering.

[mgh]

dfttest is excellent at removing compression artefacts such as blocking and also at removing the noise you get when capturing analog tv from mildly weak channels. Have seen its deblocking powers mentioned in other threads here but not in this one
Nothing else i have tried is as good as dfttest at presrving details.
thanks for a superb filter.

[lansing]

Originally Posted by tritical

Have you tried reducing tbsize and/or sigma, or running dfttest on a motion compensated version of the video? dfttest is definitely not immune to ghosting when using 3d filtering.

I get what you mean now. I decreased the tbsize to 1 and the ghosting went away. Thanks for the help.

[yup]

Hi all!
I written simple script for deblocking VCD (my daughter have big collection anime on VCD and I want transfer to DVD replace 6-8 VCD to one DVD DL) result very good.

MPEG2Source("AVSEQ01.d2v",5,6,info=3)
source=ColorMatrix(hints=true)
sigma=110*1.5
sigmamc=110
sourcef=source.dfttest_dfttest(Y=true,U=false,V=false,tbsize=1,ftype=1,sbsize=8,sosize=6,sigma=sigma)
sourcef=sourcef.dfttest_dfttest(Y=false,U=true,V=true,tbsize=1,ftype=1,sbsize=16,sosize=12,sigma=1.5*sigma)
sclip = source.msuper()
sclipf = sourcef.msuper()
vf1=manalyse(sclipf,isb=false,delta=1,overlap=4,badSAD=1000)
vf2=manalyse(sclipf,isb=false,delta=2,overlap=4,badSAD=1000)
vf3=manalyse(sclipf,isb=false,delta=3,overlap=4,badSAD=1000)
vb1=manalyse(sclipf,isb=true,delta=1,overlap=4,badSAD=1000)
vb2=manalyse(sclipf,isb=true,delta=2,overlap=4,badSAD=1000)
vb3=manalyse(sclipf,isb=true,delta=3,overlap=4,badSAD=1000)

mcomp7 = interleave(\
  mcompensate(source,sclip,vf3,thSCD1=600)\
, mcompensate(source,sclip,vf2,thSCD1=600)\
, mcompensate(source,sclip,vf1,thSCD1=600)\
, source\
, mcompensate(source,sclip,vb1,thSCD1=600)\
, mcompensate(source,sclip,vb2,thSCD1=600)\
, mcompensate(source,sclip,vb3,thSCD1=600))
chroma=mcomp7.dfttest_dfttest(Y=false,U=true,V=true,tbsize=7,ftype=1,sbsize=16,sosize=12,sigma=1.5*sigmamc).selectevery(7,3)
mcomp7.dfttest_dfttest(Y=true,U=false,V=false,tbsize=7,ftype=1,sbsize=8,sosize=6,sigma=sigmamc).selectevery(7,3)
MergeChroma(chroma)
#StackVertical(source,last)

I use different spatial block for luma and chroma, because it is YV12 and chroma resolution 2 time little than luma (please advice) .
Also I think will be useful find optimal matrix (sfile parameter) based on MPEG quantizer, but why? For analog capture I use only sigma and increase sigma for chroma.
Any suggestions, please welcome!
With kind regards yup.

[VincAlastor]

dfttest is to crazy slow for hd encoding. can i use the gpufftw library or a cuda library instead? (http://gamma.cs.unc.edu/GPUFFTW/)

[markanini]

Originally Posted by VincAlastor

dfttest is to crazy slow for hd encoding. can i use the gpufftw library or a cuda library instead? (http://gamma.cs.unc.edu/GPUFFTW/)

Wow, that would be sweet!

[Vitaliy Gorbatenko]

It seems the project abandoned. Have not updated. I think it should look for the implementation of FFT on Open-CL, as the most promising and unlike CUDA universal.

[Great Dragon]

It's a great filter you've made, tritical. Thanks.
And I have one question: can I disable completely a temporal filtering to use only spatial features?