- From: Tab Atkins Jr.. via cvs-syncmail <cvsmail@w3.org>
- Date: Tue, 02 Aug 2011 23:04:21 +0000
- To: public-css-commits@w3.org
Update of /sources/public/csswg/css3-images
In directory hutz:/tmp/cvs-serv18171
Modified Files:
Overview.html Overview.src.html
Log Message:
Reworded the premultiplied explanation note in the Color Stops section, per feedback from Brian Mantheos.
Index: Overview.html
===================================================================
RCS file: /sources/public/csswg/css3-images/Overview.html,v
retrieving revision 1.119
retrieving revision 1.120
diff -u -d -r1.119 -r1.120
--- Overview.html 2 Aug 2011 22:43:20 -0000 1.119
+++ Overview.html 2 Aug 2011 23:04:19 -0000 1.120
@@ -1031,16 +1031,17 @@
rgba() 4-tuple, one can convert this to a premultiplied representation by
multiplying the red, green, and blue components by the alpha component.
For example, a partially-transparent blue may be given as
- rgba(0,0,255,.5), which would then be expressed as (0,0,127.5,.5) in its
- premultiplied representation. Note that fully opaque colors have the same
- representation in rgba and premultiplied-rgba (you multiply the components
- by 1), and all fully transparent colors are expressed the same way in the
- premultiplied representation (you multiply each component by 0, so no
- matter what the source color was in rgba, the premultiplied representation
- is (0,0,0,0)). Interpolating colors using the premultiplied
- representations rather than the plain rgba representations tends to
- produce more attractive transitions, particularly when transitioning from
- a fully opaque color to fully transparent.</p>
+ rgba(0,0,255,.5), which would then be expressed as [0, 0, 127.5, .5] in
+ its premultiplied representation. Interpolating colors using the
+ premultiplied representations rather than the plain rgba representations
+ tends to produce more attractive transitions, particularly when
+ transitioning from a fully opaque color to fully transparent. Note that
+ transitions where either the transparency or the color are held constant
+ (for example, transitioning between rgba(255,0,0,100%) and
+ rgba(0,0,255,100%) or rgba(255,0,0,100%) and rgba(255,0,0,0%)) have
+ identical results whether the color interpolation is done in premultiplied
+ or non-premultiplied color-space. Differences only arise when both the
+ color and transparency differ between the two endpoints.</p>
<!-- ====================================================================== -->
<h2 id=sizing><span class=secno>6. </span> Sizing Images and Objects in CSS</h2>
Index: Overview.src.html
===================================================================
RCS file: /sources/public/csswg/css3-images/Overview.src.html,v
retrieving revision 1.126
retrieving revision 1.127
diff -u -d -r1.126 -r1.127
--- Overview.src.html 2 Aug 2011 22:43:20 -0000 1.126
+++ Overview.src.html 2 Aug 2011 23:04:19 -0000 1.127
@@ -774,15 +774,11 @@
one can convert this to a premultiplied representation by multiplying the
red, green, and blue components by the alpha component. For example, a
partially-transparent blue may be given as rgba(0,0,255,.5), which would
- then be expressed as (0,0,127.5,.5) in its premultiplied representation.
- Note that fully opaque colors have the same representation in rgba and
- premultiplied-rgba (you multiply the components by 1), and all fully
- transparent colors are expressed the same way in the premultiplied
- representation (you multiply each component by 0, so no matter what the
- source color was in rgba, the premultiplied representation is (0,0,0,0)).
+ then be expressed as [0, 0, 127.5, .5] in its premultiplied representation.
Interpolating colors using the premultiplied representations rather than
the plain rgba representations tends to produce more attractive transitions,
- particularly when transitioning from a fully opaque color to fully transparent.</p>
+ particularly when transitioning from a fully opaque color to fully transparent.
+ Note that transitions where either the transparency or the color are held constant (for example, transitioning between rgba(255,0,0,100%) and rgba(0,0,255,100%) or rgba(255,0,0,100%) and rgba(255,0,0,0%)) have identical results whether the color interpolation is done in premultiplied or non-premultiplied color-space. Differences only arise when both the color and transparency differ between the two endpoints.</p>
<!-- ====================================================================== -->
Received on Tuesday, 2 August 2011 23:04:22 UTC