Re: [css3-background] vastly different takes on "blur"

On 06/23/2010 01:41 PM, Brian Manthos wrote:
>>> Agreed. I was thinking to include a note about that, and then ask a
>>> question such as "which of the following renderings best describe a
>>> blur of 10px (and don't cheat to see what you browser does)", and
>>> include some variations that are all based on a black shadow (for
>>> widest range of perceptiple changes to transparent). The variations
>>> would include not only one version being twice the width of the other,
>>> but also the possibility of clipping to within some range that (1% -
>>> 99%?) that a human can discriminate as different from totally opaque
>>> and totally transparent (and filling the 10px with that), and also
>>> testing whether or not people consider a pixel of 100% and/or 0% to be
>>> part of the countable part or not.
>>
>> I feel that these other questions are much more easily resolved here, and I'd
>> rather keep the question as simple as possible for the one issue where we
>> really would benefit from feedback. Getting coherent answers from the web
>> design community is difficult enough as it is.
>>
>> ~fantasai
>
> But that completely misses a critical point.
>
> With all renderings I've seen so far, the mathematical impact of the blur
> and the human perceptible impact of the blur are significantly different.

That's something we can resolve here, though: it's not something that needs
web author input. I think it's fair to presume that the measurement should
correspond to the human-perceptible range of the blur. The details of how
to spec that is something for us to work out among spec-writers and
implementors. The question we need more *author* feedback for is whether
the value refers to a blur radius or a blur distance.

~fantasai