http://imagej.273.s1.nabble.com/downsampling-methods-tp3690444p3690446.html
>Hi Aviva,
>
>you should try Gaussian downsampling:
>
>In Fiji, there is a Javascript in PLugins->Examples->downsample
>explained at
>
>
http://pacific.mpi-cbg.de/wiki/index.php/Downsample>
>the same Javascript is at the ImageJ website
>
>
http://rsb.info.nih.gov/ij/macros/js/Downsample.js>
>or, alternatively a public API method in the packages of mpicbg_.jar
>that are part of Fiji, such that you can call it for a nopen Image, say,
>from Plugins->Scripting->BeanshellInterpreter:
>
>import ij.*;
>import mpicbg.ij.util.Filter;
>new ImagePlus( "downsampled", Filter.scale( IJ.getImage().getProcessor(),
>0.2f ) ).show();
>
>Lanczos being just an approximation of a bandpass filter in the
>frequency domain, you could also try to do the downsampling directly
>through that bandpass-filter, ImageJ has the respective functions.
>Depends very much on what you want. For most cases, the Gaussian thing
>is just optimal.
>
>Best,
>Stephan
>
>
>
>On Mon, 2009-11-16 at 08:07 +0200, Aviva Vaknin wrote:
>> Hello all!
>>
>> I have implemented a Lanczos8 kernel convolution to downsample images
>> which works well for 30-40 iterations.
>>
>> After that ringing artifacts enter, even if I reduce a 1600x1200 image one
>> pixel
>> each iteration.
>>
>> Should this be occurring ? Is there a way around it ?
>> Is there a better down sampling method for this type of problem ?
>>
>> thanks,
>> aviva