Denoising Overkill?

[Zach]

Disclaimer: I know what I'm about to ask is subjective and also depends on the source material at hand, but I am just seeking a "rule of thumb" type response from the experts.


Take this script for example:

AviSource("clip.avi") #noisy 352x240 clip
ColorMatrix()
Tweak( sat=1.2, bright=2.0, cont=1.2 )
Spline36Resize( 704, 480 )
RemoveGrain(mode=2)
FFT3DGPU( sigma=3.5, sharpen=0.4, precision=2 )


FFT3DGPU is a must because it's a great filter and produces great results, so is using RemoveGrain() after the resize overkill?

There is a difference in the resulting video if I remove it--and doing a Compare() confirms this--but in real-time, the actual difference is just on the edge of perception (you know how that goes), so I can't tell if it's better, worse, or just different. ;)

So I'm just curious what you video encoding "experts" think. As a rule of thumb, would you consider using both denoising filters? Or is that just overkill and only something you would do as a last-ditch effort to try to improve things?

[TheRyuu]

It would probably be redundant more then overkill. fft3d is very powerful by itself. Just tune the values to use it alone.

It's also like why do people use "undot()" or "removegrain(mode=1)" (same thing as undot()) in the beginning of the scripts even though another denoiser call later on will probably get the "dots". Hell, I still do it sometimes. :)

Check out the results using both or using one and see what you like the most.

[Zach]

Redundancy--now that's a great way of classifying it. :) Thanks! (Before, my thinking was analogous to doing a 2-pass encode: the first pass [removegrain] cleaned it up, and then the second pass [fft3dgpu] would then work even better since it had a cleaner source to work with.)

Check out the results using both or using one and see what you like the most.

Having anticipated this suggestion, I already covered that in my initial post:

There is a difference in the resulting video if I remove it--and doing a Compare() confirms this--but in real-time, the actual difference is just on the edge of perception (you know how that goes), so I can't tell if it's better, worse, or just different. ;)
:p

[AVIL]

Hi,

In my personal taste, pure spatial noise filters (as removegrain) blur the image. I avoid them. I agree with wizboy11. Tune FFT3DGPU and could be you can avoid the sharpening. If you like spatial filters i suggest you FRFUN7. Find it at soulhunter's webpage:

http://soulhunter.chronocrossdev.com/

Again in my personal taste, resizing and colour adjust must be the last filters in the chain.

Although visually equivalent, the better the quality, the better the clip (IMHO).

[Zach]

http://soulhunter.chronocrossdev.com/

Interesting site. He sure has a healthy ego considering most of his favorite quotes are his own. :p

[Soulhunter]

He sure has a healthy ego considering most of his favorite quotes are his own. :p Its just that I like my own humor!

Ps: Quotes updated ;P