- From: Felix Pahl <fpahl@web.de>
- Date: Wed, 11 Feb 2004 14:58:28 +0100
- To: www-svg@w3.org
In Section 15.7.1, the spec says that "The RGBA result from each filter primitive will be clamped into the allowable ranges for colors and opacity values. Thus, for example, the result from a given filter primitive will have any negative color values or opacity values adjusted up to color/opacity of zero." It needs to be clarified what happens if an operation on premultiplied values yields color values greater than the alpha value. The Adobe Viewer seems to clamp the color values down (as far as I can tell) whereas Batik clamps the alpha values up (at least in the arithmetic FeComposite filter primitive). I feel that the former tends to produce the results one would expect, but in any case the differences can be dramatic and this needs to be standardized.
Received on Wednesday, 11 February 2004 09:30:13 UTC