Posted by
Gluender-2 on
Mar 11, 2009; 9:55pm
URL: http://imagej.273.s1.nabble.com/Zooming-and-smoothing-tp3693324p3693334.html
Bob,
I'm not totally sure about interpolation used by IJ.
As far as I remember the interpolation for zooming (which from my
point of view is definitely superfluous) is bilinear for speed
reasons but the interpolation used for scaling is cubic. (Just
checked it and it appears to be so.)
Then there is this great transformation plug-in "TransformJ" that
offers a great variety of different interpolation schemes (3 cubic
types and even one quintic). Furthermore, there is the plug-in
"Resize" that offers a few interpolation schemes.
In any case you have to justify the "simulation" of a finer grid...
HTH
Herbie
-------------------
>Herbie, Gabriel, Volker, and everyone,
>
>I prepare my acoustic images by computing them on a coarse grid
>(related to the phased array resolution) and then interpolating to a
>finer grid for presentation. I found that the bilinear
>interpolation in ImageJ was not doing what I needed, so I wrote a
>bicubic interpolation code by extending the FloatProcessor class and
>overriding getInterpolatedPixel. There are other bicubic
>interpolation plugins available for ImageJ, including an example
>from the Burger and Burge book, but in each case the interpolation
>is part of something else, not a direct effort to extend ImageJ. I
>posted my code on my web site last year in the hopes that someone
>would run with it by implementing the algorithm for the other image
>types and offering it to Wayne. I was a little tentative because I
>was not sure that my somewhat invented algorithm would work out.
>I've been using it a lot, and it seems to be perfect for my needs.
>If it is time for ImageJ to go bicubic, here is a simple path for
>it. I do not have time to do the coding right now.
>
>Bob
>
>
>Robert Dougherty, Ph.D.
>President, OptiNav, Inc.
>4176 148th Ave. NE
>Redmond, WA 98052
>(425)891-4883
>FAX (425)467-1119
>www.optinav.com
>
[hidden email]