Re: [Inkscape-user] What does the blur value relate to?

Bill Baxter wrote:

... Very nice feature though, this blurring. Does it by any chance use this: http://incubator.quasimondo.com/processing/fast_blur_deluxe.php ?

No, the current release just uses a normal Gaussian blur filter using a straightforward convolution (in combination with subsampling when you select anything but Best as filter quality). In SVN there is also code for using an infinite-impulse response filter, which might be somewhat similar to what the page you linked to does, but as far as I could see it's definitely not the same. (If you're interested there are some references in the code to the papers on which the code is based, see nr-filter-gaussian.cpp.)