RE: bits per color component.

Yes, I think we've noticed that anomoly. The starter functions in
DISelect are merely wrappers around the Media Queries functions, so the
interpretation should be exactly the same. I'm sure the wording can be
clarified. With this in mind, and observing the MQ definition [1] I
think the definition should be:

'In a device with indexed colors, the di-cssmq-color function will
return the minimum number of bits per color component in the lookup
table.'

Thus, for the common case of 5 bits red, 6 bits green, 5 bits blue (16
bits total), "di-cssmq-color(8) > 5" would be false. (Because "5 >
5" is false.)

---Rotan

[1] http://www.w3.org/TR/css3-mediaqueries/#color



-----Original Message-----
From: public-diselect-editors-request@w3.org
[mailto:public-diselect-editors-request@w3.org] On Behalf Of Chris
Lilley
Sent: 31 May 2006 20:56
To: public-diselect-editors@w3.org
Subject: bits per color component.


Hello public-diselect-editors,

under  9.9 The di-cssmq-color function
http://www.w3.org/TR/2005/WD-cselection-20050502/#sec-dcn-cssmq-color

I read:

 "number of bits per color"

Please clarify this by changing to "number of bit per color component"
which is, I think, the assumed meaning. For example, a truecolor display
with 8 bits of red, 8 bits of green and 8 bits of blue would be
described here as having 8 bits, not as 24 bits, so

di-cssmq-color(8) < 9

would be true.

The wording needs to be clarified because it is common to talk of both
the number of bits in total and also the number of bits per component. A
typical computer display might be described as a "24bit display" and a
higher quality, medical imaging display might be described as a "10 bit"
display (10 per component; 30 in total).

Also, for the common case of 5 bits red, 6 bits green, 5 bits blue (16
bits total) is di-cssmq-color(8) > 5 true or false?

-- 
 Chris Lilley                    mailto:chris@w3.org
 Interaction Domain Leader
 Co-Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG

Received on Wednesday, 31 May 2006 20:17:24 UTC