Calculates the kernel size given the standard deviation. \n
* If sdtdev is negative its magnitude will be used as the kernel size.
*
* \verbatim im.GaussianStdDev2KernelSize(stddev: number) -> kernel_size: number [in Lua 5] \endverbatim
* \ingroup convolve
Calculates the kernel size given the standard deviation. \n * If sdtdev is negative its magnitude will be used as the kernel size. * * \verbatim im.GaussianStdDev2KernelSize(stddev: number) -> kernel_size: number [in Lua 5] \endverbatim * \ingroup convolve