other resize-methods?

[Shootist]

Hi,
I`ve read an article about resizing pictures taken with digicams. There was written, that Lanczos isn`t the best method. Thzey said something about Genuine Fractals and S-Spline. Does anybody know something more about this topic. Is it possible to use this methods in avisynth-scripts too?

[Blight]

Don't know about S-Splines, but fractal resizing is considered quite heavy... It may grind any encode to a halt.

[Shootist]

So Lanczos is the best way if you look at performance and result?

[sh0dan]

S-spline is a commercial program for upsizing - not an algorithm. It applies after-resize filters depending on the source material, so it sharpens the image based on how sharp the original were. Seems rather nice, and produced better results than resize/unsharp mask.

"Genuine Fractals Print Pro" works by adding detail to the image not necessarily there from the beginning. This is simililar to the effect of adding noise in ffdshow - it gives the appearance of better quality than actually exists.

The info was found on this page (thanks google) (http://www.shortcut.nl/redirect.php?page=moreinfo.extra&id=sspline2).

The reasons why they are not that useful:
* Both methods are for upsizing, they aren't better for downsizing. Lanczos is still the detail king here. My estimate is that 95% of all resizes in AviSynth are downsizes.

* Speed (they will be _very_ slow).

* The added detail will make them much harder to compress.


For video, I _think_ these methods are some of those that sound great (and too many people talk about), but isn't of much practical use. (Who said de-convolution <sigh>)

[scmccarthy]

So, to sum up, Lanczos keeps the most detail without adding noise. Is there such thing as a detail to noise ratio?;)

Stephen

[HarryM]

Do exist any resize algorithm with spatial filtering side effect?

[trbarry]

The BiLinearResize has a triangle filter built in. And you can jigger the parms to BiCubicResize to make it adjustably softer.

- Tom