Re: ISSUE-2317 (feGaussianBlur stdDeviation=0): Give different result for feGaussianBlur stdDeviation=0 [SVG Full 1.1]

On Tuesday, April 6, 2010, 10:26:29 AM, Erik wrote:

ED> I agree that it's more intuitive to let stdDeviation="0 0" mean that the
ED> filter just returns the filter input unchanged (that is: no blur applied),
ED> and that having e.g stdDeviation="25,0" should mean that the blur is only
ED> applied in the direction where there's a non-zero value.

ED> I have ACTION-2189 to clarify this in the filters spec.

In general we have in the past tried to allow zero values in attributes and properties so that animation or script can change the values up to zero (or past, in the case of attributes or properties that allow negative values) without producing a discontinuity or putting the document in an error/undefined state.

In this specific case, a simple if..then seems appropriate in the definition. I also agree that one-dimension blurs should be allowed. Especially as gaussian blur is often computed as multiple box blurs, so this falls out nicely as an optimisation.




-- 
 Chris Lilley                    mailto:chris@w3.org
 Technical Director, Interaction Domain
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG

Received on Tuesday, 6 April 2010 12:29:50 UTC