A follow-up to this article with clarifications and corrections to the “real-world considerations” can be found here.
I researched gaussian blur while trying to smooth my Variance Shadow Maps (for the Shadow Mapping sample) and made a pretty handy reference that some might like… I figure I’d post it for my first “Tips” blog post. :)
The full article contains a TV3D 6.5 sample with optimized Gaussian Blur and Downsampling shaders, and shows how to use them properly in TV3D. The article also contains an Excel reference sheet on how to calculate gaussian weights.
Update : I added a section about tap weight maximization (which gives an equal luminance to all blur modes) and optimal standard deviation calculation.