looking for a good sharpener to follow deringing

[raido]

I am using a source that has what I think is referred to as haloing or ringing. Here is a pic (http://i50.tinypic.com/ft5oy.png) of what I'm talking about. You can see this effect around the lines of her shoulder and head. I tried using dehalo_alpha and hqdering. Hqdering didn't work very well. Dehalo_alpha worked but blurred the picture too much for my tastes. I followed dehalo_alpha with various sharpening scripts but all they did was make the ringing/haloing show back up. Is there a good sharpening filter that I can follow dehalo_alpha with that doesn't make the halos reappear? Thanks.

[Emulgator]

Try SSSharp2(rad=0.5, strength=2) or MedSharp2(str=2).

[raido]

Thanks. I found MedSharp2 here...
http://forum.doom9.org/showthread.php?p=1425066

However, I cannot find SSSharp2. Where is it? Thanks.

[Bloax]

Unfortunately, I only know SSSharp - which is Super Slow Sharpen (http://forum.doom9.org/showthread.php?t=132330).

[jmac698]

Umm. ringing and blurring are mathematical tradeoffs in a linear filter.

http://svn.int64.org/viewvc/int64/resamplehq/doc/kernels.html

[raido]

Umm. ringing and blurring are mathematical tradeoffs in a linear filter.

http://svn.int64.org/viewvc/int64/resamplehq/doc/kernels.html

Nice article. I have always used lanczosresize for my videos. I tried some of the softer resizers and the amount of ringing was reduced somewhat. Perhaps I should switch to something softer for my anime. Bicubic perhaps?

[TheSkiller]

That, or also try Spline16Resize(). :)

Spline16Resize() is my favorite resizer for downsizing and slight upsizing. For larger upsizing (more than 2 times the source), I use nnedi3 beforehand.

[Didée]

In particular for downsizing, don't underestimate ye old bicubicresize. "Configurable sharpness", and for free. ;)
Btw, for downsizing I'm often in favour of "bicubic with negative 'b' ", like e.g. bicubicresize(1280,720,-.5,.25). Neagtive b is hideous for upscaling, but comes very nice for downsizing. New rule: "b + 2c = 1 // for upsizing", and "b + 2c = 0 // for downsizing".

[*.mp4 guy]

Unfortunately I have to disagree very strongly with these recommendations. Spline16 was subtly broken last time I checked. Additionally bicubic isn't good (it is acceptable), and even if it was good I still couldn't recommend adjusting it under general usage conditions, b=0.5 c=0, the end. For low ringing, use blackman. For high sharpness, use blackman. Use from 3 to 5 taps for final downscaling, but for preserving sharpness prior to downscaling by a significant factor, up to 7 is acceptable.

If you want better aliasing performance then blackman can provide, you're pretty much stuck, because anything more aggressive will cause artifacts. That's not to say that there isn't anything better (there is) it's just not widely used or currently available in avisynh or NLE's.

[raido]

I used bicubic resize on my anime content as opposed to lanczos resize and the deringing was less noticeable. It looks like I was introducing ringing with lanczos. I have never used blackman but I will give it a shot. I see that blackman resize uses an int argument called taps. What does taps do?

[StainlessS]

Taps, See LanczosResize

http://avisynth.org/mediawiki/BlackmanResize

[Gser]

What's wrong with using spline64?

[raido]

I gave blackmanresize a go. It's pretty good, but I didn't notice a significant difference when it came to haloing compared to the bicubicresize recommendations that Didee gave me. Maybe the differences would be more noticeable using a different source.

[Gser]

Unfortunately I have to disagree very strongly with these recommendations. Spline16 was subtly broken last time I checked. Additionally bicubic isn't good (it is acceptable), and even if it was good I still couldn't recommend adjusting it under general usage conditions, b=0.5 c=0, the end. For low ringing, use blackman. For high sharpness, use blackman. Use from 3 to 5 taps for final downscaling, but for preserving sharpness prior to downscaling by a significant factor, up to 7 is acceptable.

If you want better aliasing performance then blackman can provide, you're pretty much stuck, because anything more aggressive will cause artifacts. That's not to say that there isn't anything better (there is) it's just not widely used or currently available in avisynh or NLE's.Since you like blackman have you tried blackmanminlobe that comes with DitherTools?

[*.mp4 guy]

Yes... it is quite a bit worse then what I actually use. More surprisingly it also looks worse then blackman. The first negative lobe appears exaggerated, though successive lobes are indeed well suppressed. However I really don't care for primary negative lobe overshoot, and so I actually prefer standard blackman (though I don't actually use it very often). I would surmise that the minimum lobe version of blackman falls off of a cliff before the third lobe (with around 5 taps) which would cause the second lobe to look overemphasized. This could be countered by using a lower number of taps, but with 3 taps blackmanminlobe produces a remarkable amount of aliasing.

[edit: added response]
What's wrong with using spline64?
It is also slightly broken, but in the opposite direction of spline16 (spline64 causes a bit of blur). It also doesn't appear to give the improvement I would expect in aliasing performance when compared to spline36, so it ends up being a loss on all fronts.