I was reading the
getGaussianKernel documentation it mentiones the following about how sigma is computed when given a non positive value:
sigma: Gaussian standard deviation. If it is non-positive, it is computed from ksize as
sigma = 0.3*((ksize-1)*0.5 - 1) + 0.8
I was wondering where such computation is derived from.
Thanks in advance!
IIRC that’s figuring about 3 sigma in the kernel size, with some fiddling for rounding reasons.
a gaussian distribution has 99.7% of its probability mass within 3 sigma. that’s good enough for 8 bits of precision.
plug some values in, consider the result.
Yes, thanks, that makes sense. I was not sure if the fiddling part had a different reason behind it or not.
Thanks a lot!
Posted something else but realised the calculation was for sigma, not for ksize. Thanks again!