Re: Convolve with kernel size > 25

Posted by Michael Schmid on
URL: http://imagej.273.s1.nabble.com/Potential-updates-to-ImageJ-a-question-tp5011598p5011634.html

Hi Herbie,

there is no obvious problem that I see for large vs. small normalized kernels.
Normalized kernels don't work well if the sum of the kernel elements is very close to zero: "Normalized" means that the kernel is divided by the sum of the elements, and devision by a very small number gives huge numbers as output. Maybe that is the reason for your problem?

Michael
________________________________________________________________
On Feb 17, 2015, at 14:00, Herbie wrote:

> Dear experts,
>
> (with IJ version 1-49o) I feel unable to convolve images with _normalized_ kernels of side lengths greater 25 pixel (e.g. 27).
>
> I encounter no problems without normalization.
>
> Best
>
> Herbie

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