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Old 25th February 2012, 15:57   #1074  |  Link
-Vit-
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Join Date: Jul 2010
Posts: 448
Quote:
Originally Posted by horrormaster34 View Post
sharpening, denoising, noise stabilizing
You will get a little of all three if you provide only a preset and no other settings. QTGMC is not really trying to be a sharpener or denoiser, this happens mainly a byproduct of the processing used to avoid shimmer. The light temporal smoothing / denoising improves compressibility, and the sharpening provides some detail enhancement. Despite the fact that this moves the result away from the source, most people like those effects.

The impact on noise is often very minor, and you may not care to do anything about it, especially since it will involve more processing. However, some people do take the sharpness down, and that's a free operation, e.g. Sharpness=0.4 or 0.7

However, if you really want something that's *very* close to the source, then Boulder's suggestion above is the right way to go about it. Although his MatchPreset choice is very high and will slow it down - I would usually leave that out and set an explicit Preset for clarity:
Code:
QTGMC(Preset="Slower",SourceMatch=2,Lossless=2,EZKeepGrain=0.5,Sharpness=0.1)
SourceMatch specifically tries to make the deinterlace as "lossless" as possible without introducing shimmer. EZKeepGrain helps preserve the noise from the original. These are not default settings because I think most people want the slight denoise/enhance. Also these settings are slower - you can speed up the Preset a little without any major loss. I would strongly suggest an MT setup (see the first post).

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On a related note, there was a flurry of activity a couple of days ago when the MSU Deinterlacer v2.0 was released. They released it with a "paper" that "showed" their deinterlacer beat all the competition (including QTGMC) on PSNR and SSIM tests (I use the word "paper" loosely - results without critical points of methodology such as settings). Those metrics alone are a very poor measure of deinterlacing quality as Didée demonstrated - their deinterlacer fails terribly on real world samples.

However, I mention this here because the SourceMatch/EZKeepGrain settings above greatly increase the performance of QTGMC on such metrics, without any significant ill-effects except performance. Some quick testing with the line above puts QTGMC in line with MSU v2.0 on SSIM, but without all the nasty visual problems of MSU.

Last edited by -Vit-; 25th February 2012 at 17:42.
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