- From: fantasai <fantasai.lists@inkedblade.net>
- Date: Fri, 11 Jun 2010 17:21:34 -0700
- To: Brian Manthos <brianman@microsoft.com>
- CC: Brad Kemper <brad.kemper@gmail.com>, Simon Fraser <smfr@me.com>, "L. David Baron" <dbaron@dbaron.org>, "www-style@w3.org" <www-style@w3.org>
On 06/11/2010 04:58 PM, Brian Manthos wrote: > Testability question. > > As we converge on the final language, can we make sure that it expresses where -- > regardless of specifics of blur algorithm -- a test harness could check for fully > transparent or fully opaque pixels? > > What I mean is that there should be a no-man's-land beyond the edge of the > specified blur region where no blurred pixels should be found. > > > My impression is that the intentional flexibility in the specification is > (a) about how the blur ramps up / down -- linear, exponential, etc. -- and > the impact of neighboring pixels and (b) NOT about allowing the blur to > bleed off to infinity or to shrink to barely perceptible. The current spec wording was the best I could come up with when someone told me "it's underspecified what blur means". As Simon points out, it's not actually correct wrt the original spec's intention. I don't know enough about graphics to tell whether we can actually check for fully transparent or fully opaque pixels under a blur algorithm. Someone else will have to answer that. But as far as testability is concerned, even if we allow algorithms that have an infinite die-off, we can (and probably should) restrict it to a certain percentage, e.g. check for < 1% or < 0.1% opaque in the "transparent" region, and > 99% or > 99.9% opaque in the "opaque" region. ~fantasai
Received on Saturday, 12 June 2010 00:22:12 UTC