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Gaussian blur

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Gaussian blur Artur Rataj 18 Mar 19:50
Gaussian blur William Skaggs 20 Mar 20:14
Artur Rataj
2006-03-18 19:50:25 UTC (over 18 years ago)

Gaussian blur

Hello, can anyone point me to some reference of the algorithm? Why the translation radius -> std dev is so strange? I. e. why it involves 0xff. Btw, this method is inprecise for values greater than 0xff.

Cheers, Artur

William Skaggs
2006-03-20 20:14:53 UTC (over 18 years ago)

Gaussian blur

Artur Rataj wrote:

Hello, can anyone point me to some reference of the algorithm?

I don't know the exact source that the programmers were referring to, but if you google for "fast gaussian blur" you will find plenty of references.

Why the translation radius -> std dev is so strange?

My understanding is that it is basically a kludge. Simply using the specified radius as the standard deviation of the Gaussian would be the "natural" thing to do, but the result looks like it smears things more than the user expects. The formula used by GIMP, I think, is just an attempt to set a radius that makes a sharp dot look perceptually like a fuzzy circle with something like the specified radius.

-- Bill


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