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Old 29th February 2012, 06:32   #55  |  Link
yup
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Join Date: Feb 2003
Location: Russia, Moscow
Posts: 854
Hi all!
I suggest variance value relative low for this purpose.
I try find relation between radius for Gaussian blur and variance, i find two approaches:
from Gimp
sigma=(radius+1)/sqrt(2*log10(255))
variance=sigma^2=(radius+1)^2/(2*log10(255))
from common knowledge about normal distribution
3*sigma=radius
variance=radius^2/9
Both give higher value variance for local contrast enhancement from 250 to 2000 and for this value I see increase contrast even at strength 0.4.
Please confirm my calculations.
yup.
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