Sets the amount of blur to be applied to the image.
HRESULT SetStandardDeviation( float amount );
The amount of blur to be applied to the image. You can compute the blur radius of the kernel by multiplying the standard deviation by 3. The units of both the standard deviation and blur radius are DIPs. A value of zero DIPs disables this effect entirely.
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.