Grayscale, lacuna value, and optional argument

Hello,

The ED of filters says that the lacuna value for the grayscale filter is zero.
  https://drafts.fxtf.org/filters/#FilterProperty

However:

 - the syntax does not seem to allow the argument to be omitted so how
   can the lacuna value be used
 - if it did, then 0 is an odd value

0 means no change. Thus seems unintuitive. I would expect grayscale()
to be equivalent to grayscale(100%) which is likely what authors would
expect and would be convenient for the most common use case "make this
grayscale".

Suggested fix:

 - change the grayscale filter syntax to make the argument optional
 - change the lacuna value to 1

Btw I added some tests for grayscale since there was only one (100%)
so I added 1, 0, 0% and 300% as well.

-- 
Best regards,
 Chris  Lilley
 Technical Director, W3C Interaction Domain

Received on Monday, 1 February 2016 22:02:58 UTC