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| misterhatoola |
| Posted: Jan 2 2003, 02:46 PM |
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Unregistered
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Hi VDub masters.
Listen, I have a somewhat known situation: I have captured video footage from an analog VHS source, and - how unexpected - it has a lot of red/blue chroma spots in all the frames! That is due to several faults: The camcorder was an old Video8 one; the tape was used; my capture card is extremely bad; and the compression was something that you should sue me for. But I have to live with this, since the original tape is long gone, so that crappy AVI file is all I have.
Now, I know that my luminance channel is quite fine, and I don't want to touch it; the problem is with the chrominance channels, so I would like to handle and improve ONLY the chrominance channel. I have tried several filters, and here is what I came up with:
1. rmPal - no good. My problem is not lines, but spots that keep appearing and disappearing each and every frame.
2. flaXen's VHS Stabilizer - in the beggining I was really impressed with this filter, but I came to realize that it produces HORRIBLE artifacts with moving thingies. Yes, I can smooth the artifacts out with a blur/noise reduction filter, but I want to keep my picture as clean as possible, and not to touch my luminance channel.
3. Chroma noise reduction - sorry, no good too. It kept all the spots.
4. Temporal cleaner - no good too. Still spots, although a bit less visible.
5. Any other cleaners or any filters that mess with my luminance - no! Leave my luminance alone! It's the only thing that's worth anything in my AVI!
6. And finally, the half-Messiah: Avery Lee's (internal VirtualDub) TV filter. When I set it to "I/Q 5x5 avg/temporal soften" it simply does wonders to my video. Suddenly the grey wall isn't red and blue all the time - it stays grey! Hurray to Avery!!! But, it seems that the nice temporal soften thingie doesn't have a threshold, so when objects move from place to place, they leave a lovely trail of their color that takes a few frames to disappear.
So, all I want you is to recommand me (or simply make one, it shouldn't be hard, you just take Avery's source code and add a threshold) of a filter that complies to these criteria:
A. It handles ONLY the chrominance channels.
B. It averages the chroma by 5x5.
C. It applies a temporal softening to the chroma, BUT has a threshold that could be changed via GUI!!!
That is all I ask of you. If someone could grant me my wishes, I will be forever in his debt. And he'll feel good about himself for making a good deed indeed.
Thankfully,
Mister Hatoola.
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| Morsa |
| Posted: Jan 4 2003, 09:21 PM |
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Moderator of the Vdub support board
Group: Moderators
Posts: 640
Member No.: 246
Joined: 9-September 02
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I don't understand very well what you want or need.
Filtering that kind of noise from VHS is a difficult task with the filters we've got now.
Could you post a little example?
I suggest you to capture to Huffyuv, 720x480, upsize to something around 2x, apply chroma noise reduction filter or Smart Smoother IQ, dynamic noise reduction, downsize again to 720x480 and see what happens. |
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| jcsston |
| Posted: Jan 5 2003, 05:32 AM |
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Matroska Dev
Group: Moderators
Posts: 553
Member No.: 652
Joined: 3-November 02
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| QUOTE (Morsa @ Jan 4 2003, 03:21 PM) | | upsize to something around 2x, apply chroma noise reduction filter or Smart Smoother IQ, dynamic noise reduction, downsize again to 720x480 |
Can I ask what resizes you use when upsizing and downsizing?
I've read on an older post that you used Lanzcos3 when supersampling, but do you resize up and down with it?
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Use the Matroska file format |
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| misterhatoola |
| Posted: Jan 5 2003, 03:31 PM |
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Unregistered
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Hi.
Morsa, all I'm looking for is a modified TV filter - someone who took the internal VirtualDub TV filter and enhanced it. I've got the best video output from the TV filter set to "5x5 average + temporal soften", and all I'm looking for is a filter that does the same job, but that its temporal softening has a definable threshold: instead of blending a pixel's chroma with the correspondant one in the previos frames, I want it to check how big is the difference between the current and previos chroma value, and not to replace the chroma if the difference is bigger than the value I entered it.
Oh, that didn't turn out very understandable. Sorry. Try this:
Wait, it didn't turn out understandable either.
Mister Hatoola. |
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| Morsa |
| Posted: Jan 5 2003, 04:45 PM |
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Moderator of the Vdub support board
Group: Moderators
Posts: 640
Member No.: 246
Joined: 9-September 02
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Yes, I use Lanczos3 for upsize and downsize, but you can try what you like.
Remember that Smart Smooth IQ makes miracles on chroma noise and combined with Dynamic noise reduction on high resolutions the results are amazing. |
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| misterhatoola |
| Posted: Jan 5 2003, 06:40 PM |
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Unregistered
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Hurray Smart Smoother IQ!!! Hurray Tim Park!!!
Finally, exactly what I looked for. Took me a while to find, but it really does do miracles. Thankyou everyone for your kind help, and sorry I was such a pain in the ass.
Behold, the wonder of Smart Smoother IQ (these images are pretty heavy, but that's 100% lossless PNG...)!!!
Before:
And after:
It's amazing!!! Look at their faces! Watch the top left corner, with all the red and blue spots! It's a miracle!
Thankyou Morsa.
Mister Hatoola. |
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| misterhatoola |
| Posted: Jan 7 2003, 08:54 AM |
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Unregistered
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If the images don't load, go to:
http://www.geocities.com/Mr_Hemulin_Flower...rs_2/before.png
and:
http://www.geocities.com/Mr_Hemulin_Flower...ers_2/after.png |
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| Morsa |
| Posted: Jan 7 2003, 08:59 AM |
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Moderator of the Vdub support board
Group: Moderators
Posts: 640
Member No.: 246
Joined: 9-September 02
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if you have a geocities page you can't link directly to a file, instead make an html page with the two pictures inside. |
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