Re: Zooming new problem

Posted by Burger Wilhelm on Mar 11, 2009; 8:53pm
URL: http://imagej.273.s1.nabble.com/Zooming-and-smoothing-tp3693324p3693337.html

Hi Bob,
 
as you mention, we have listed a number of different interpolation methods in the source section of our website (imagingbook.com), including cubic and other spline methods. I particularly recommend the Catmull-Rom formulation for good results. I can also send you code for a Lanczos interpolator, which has no visible advantage though.
 
All these methods are pretty standard and implemented by stand-alone code that could be copied directly into ImageProcessor's getInterpolatedPixel() method and selected using a suitable mode switch.
 
Wilhelm

________________________________

Von: ImageJ Interest Group im Auftrag von Robert Dougherty
Gesendet: Mi 11.03.2009 20:25
An: [hidden email]
Betreff: Re: Zooming new problem



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.
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