LanczosResize vs. SplineResize

[Jeremy Duncan]

Filter Support Taps
Point 0.0001 1
Bilinear 1 2
Bicubic 2 4
Spline16 2 4
Lanczos 3 6
Spline36 3 6
Lanczos4 4 8
Gauss 4 8

This info is from IanD in this thread, first page.

I know I can set ffdshow to resize using lanczosresize, 2 taps.
But the chart I got from ianD shows that in avisynth, lanczosresize uses 6 taps.

So, my question is. Looking at the chart. Does avisynth lanczosresize use 3, or 6 taps?

Also, a quote from IanD,

"All resizers use the same lookup table based MMX/SSE code."

Is this quoted "Code", in SSE only?

Can it be updated to SSE4 or SSE2?

[IanB]

LanczosResize use 6 taps (sampling points).

The resizer generates code appropriate to the processor.

It could be updated, but it is already quite fast and other avisynth code has more pressing need of work.

[DeathTheSheep]

Does anyone here still have Wilbert's old splineW filter (.dll posted earlier in this thread, but dead link)? I'm in need of his oversharp spline16w...

[Wilbert]

http://www.geocities.com/wilbertdijkhof/newresize_04032007-2.zip

[DeathTheSheep]

Thanks, I appreciate it!

DTS

[Gavino]

I also put Keys paper up (http://karton.student.utwente.nl/01163711.pdf) if you are interested, it gives the exact coefficients for spline16/36 optimized to match the first 3/4 terms of the Taylor expansion of the signal.
Has anyone got another link for this paper? - this one (two years old) appears to be dead.

[mikenadia]

googling, I found this. I do not know if this is the one you are looking for.
http://www.cs.sunysb.edu/~vislab/papers/volvis96_Taylor.pdf (p5)

[Gavino]

Thanks - that looks relevant, but I was also interested in the original paper by R.G.Keys - "Cubic Convolution Interpolation for Digital Image Processing" (actually referenced in your linked paper).

I've tried Googling, but found only abstracts or references, not the paper itself.

[Wilbert]

Thanks - that looks relevant, but I was also interested in the original paper by R.G.Keys - "Cubic Convolution Interpolation for Digital Image Processing" (actually referenced in your linked paper).

I've tried Googling, but found only abstracts or references, not the paper itself.

http://rapidshare.com/files/239398655/01163711.pdf.html

[Gavino]

Thanks, Wilbert - that's the one. :thanks:

[mikenadia]

In the last page of the Keys paper, they point out to two different "boundaries" ( or "additionnal" conditions (to match the Taylor series expansion of the sampled function for as many terms as possible) as being may be more optimal (highest order of convergence) and not "second derivatives at endpoints=0". For Spline36 and over.
http: //www.ugrad.cs.ubc.ca/~cs303/2005W2/Handouts/piecewiseCubic.pdf ( 1st paragraph p3)
Thanks. Nice paper.

[IanB]

@mikenadia,

Is this the full URL? http://www.ugrad.cs.ubc.ca/~cs303/2005W2/Handouts/piecewiseCubic.pdf (http://www.ugrad.cs.ubc.ca/~cs303/2005W2/Handouts/piecewiseCubic.pdf)