really strong chroma artifacts over the whole frame

[dexy]

Here is a some clip I have recorded from broadcast. I posted some frames here, so you can see how it is looks like(my connection is too slow, so I have posted only some pictures not a HQ video). There is some noise but it can be easilly removed couse it is in luma. The problem is in chroma, I have used some filters like guava comb, but I haven't seen any difference even with high setting. Also I have tryed wavelet noise reduction by the jam(using virtualdub, so I can see the preview), this filter greatly works with luma, but cannot remove this kind of chroma (filter can recognize artifacts (set preview to high), but it can't remove it). if you have this filter, try to load some of this pictures in Vdub, so you can see what I am talking about. Well, I also have tryed, derainbow function for avisynth, and I am currently testing fft3d by fizics, but, as I can see this is the same story like that with previous filters. Does somebody have some idea how to remove it?
samples:

5993

[Guest]

I approved your first attachment only, because they are very large and all show the same thing.

[IanB]

@Neuron2, a 2nd example might have been helpfull to see if the pattern is fixed or moving.

@dexy, If the pattern is fixed mask it out with an inverse pattern like you would remove an alpha blended logo. However I suspect it is not going to be fixed, and by the look of the example the interference frequency changes from top to bottom. This is going to be hard to remove.

Maybe you could strip the colour and then colourize it.

[Chainmax]

Making a second capture and averaging helps with luma noise, can it help with chroma noise? If not (or dexy can't make a second capture), how about this:

- First, use TemporalSoften(2,0,50,mode=2)

- If that's not enough, add CNR2("xxx",4,5,255)

- If that's not enough, add FFT3DFilter(sigma=6,plane=3,bw=32,bh=32,bt=3,ow=16,oh=16)

- If that's not enough, use a higher sigma value in the FFT3DFilter line until the artifacts disappear.

After all this, the picture will have lost a lot of color. On a recent filterchain, using Tweak(sat=1.4) helped a lot with that issue. Try using that, maybe with higher sat values.

[Wilbert]

It sounds more like a hardware problem to me.

[dexy]

@neuron2 I have posted first preview so you can see red and green line, second and third to see that it is moving, fourth to see combinations of red&green lines and blue&yellow lines, and finally fifth prewiev to see blue and yellow lines only. Please bring back 1st,2nd,4th, and 5th preview, or tell me how to post mpeg2 clips.

It is actually the best to post two videos, so that moving can be seen. One with red/green combination and second with both and blue/yellow combination.

@wilbert Note, this is not analogue capture, and it is not some hardware problem, this is capture from broadcast(pal b), so this artifacts are caused by bad tv signal.

@IanB I will try to explain this moving. This lines are moving very fast from left to right and reverse. As you can see in case of the first background (singer playing piano) there are mostly red/green lines, and in case of the second background (second singer) there are most blue/yellow lines. But there is third case too, when can be all lines seen, but in this case (fourth preview) lines are smaller and there is smaller space between them.

@Chainmax I will try this today and tell you if it is working. Thanks!

[Guest]

tell me how to post mpeg2 clips Upload it to one of the numerous free upload sites and then post a link.

Are you saying that you captured the original transport stream? Or was the MPEG you want to show us encoded by you or a hardware encoder, possibly in a DVD recorder or capture card? Please give as many details as possible about the capture methodology and signal source.

[Trixter]

Note, this is not analogue capture, and it is not some hardware problem, this is capture from broadcast(pal b), so this artifacts are caused by bad tv signal.


There is no way to remove interference like that without removing the colors that make up the interference. Your best bet is to strip all chroma and then clean up (denoise) the remaining B&W image.

[Mug Funky]

defreq _might_ be able to help, as could fanfilter.

setting them up is another story... the problem doesn't crop up enough for there to be a really straightforward guide to using defreq. i believe fanfilter is a little easier to use.

at the very least they could tame that pattern to the point where something like peachsmoother could grab hold of it without destroying the good chroma.

[dexy]

@chainmax

I have tryed this, I have used larged sigma too (I have set it to 100 000 (I didn t know which is the highest setting, so I have set some big number)). I haven t use tweak couse this brings back artifacts too. As you can see, a lot of artifacts are removed, but there can be seen some of them which are not removed:sly: . I have posted difference freme too.;)

6005

6006

@neuron2

I have captured clip via "asus silicon wdm video capture" tv card using InterVideo Home Theater software. This software capture clip into mpeg2 streem. I have choosed
"better" profile (resolution 352x576; bit rate 3600; frame rate 25). Video standard is PAL B.:cool:

@trixter

Your best bet is to strip all chroma and then clean up (denoise) the remaining B&W image.

How can I do it?

@mug funky

As I understand, this filters are builded for some cases like this? If you are sure that this filters are solution for my problem, let me know how to setup them.

[Guest]

Unless I missed it, you still haven't told us what the input signal to the capture card is.

[Mug Funky]

PAL B = composite AFAIK.

[dexy]

I m sorry, I forgot, antenna input (or RF if you like to call it that). It is not composite and it is not s-video..

[Chainmax]

Try this then:

SpatialSoften(4,0,60)
TemporalSoften(4,0,60,mode=2)

and increase the "4" in steps of 1 and the "60" in steps of 10 if needed. Or try following Mug Funky's advice.

[Revgen]

Unless I missed it, you still haven't told us what the input signal to the capture card is.

I use an S-VHS deck myself to record Cable TV and also get color interference simply from the bad signal. I've never seen any of these problems from a clean source whether using s-video or composite.


@dexy

Try buying an aftermarket TBC. This may help clean up the signal before it goes to your comp.

[dexy]

@chainmax

I have tryed this too, even including fft3d filter; clip is near to grayscale, and some of artifacts are sill present. Do you have some other idea?

@mug funky

Please tell me how to setup this fiters?

@revgen

Well, I stil dont have cable tv (it will be soon installed I hope so), and that is the main problem, this signal is from air tv.

[dexy]

I have finally posted those two clips

http://www.badongo.com/vid/173578
http://www.badongo.com/vid/173593

I have tryed fanfilter and defreq, but I supose that those filters are basicaly for fixed lines, which are not in my case.