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RE: Suggested edits for guidelines 1.4 CONTRAST

From: Gregg Vanderheiden <gv@trace.wisc.edu>
Date: Fri, 24 Feb 2006 09:10:21 -0600
To: "'Makoto UEKI - Infoaxia, Inc. -'" <ueki@infoaxia.co.jp>, <w3c-wai-gl@w3.org>
Message-ID: <002e01c63954$6e9962e0$ee8cfea9@NC6000BAK>

Agree

Have fixed this.

Thanks

Gregg

 -- ------------------------------ 
Gregg C Vanderheiden Ph.D. 
Professor - Ind. Engr. & BioMed Engr.
Director - Trace R & D Center 
University of Wisconsin-Madison 
The Player for my DSS sound file is at http://tinyurl.com/dho6b 

-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org] On Behalf
Of Makoto UEKI - Infoaxia, Inc. -
Sent: Friday, February 24, 2006 8:36 AM
To: w3c-wai-gl@w3.org
Subject: Re: Suggested edits for guidelines 1.4 CONTRAST


Hello Gregg,

This is easier to understand and to be tranlated than the old definition.
It was hard for me to understand this definition when I tried to translate
it into Japanese.

<blockquote>
> luminosity contrast ratio
> {{(L1 + 0.05) / (L2 + 0.05), where L1 is the luminosity of the lighter 
> of the text and background colors, and L2 is the luminosity of the 
> darker of the text and background colors.
</blockquote>

I think we'd better say:
- lighter of the text "or" background colors
- darker of the text "or" background colors

If we say "and", they look like "both the text and background colors" to me
and it is confusing a bit. In the old definition, it said "the higher value
(of text or background)". I just want to clarify what we mean by this
definition. 


Cheers,
Makoto


On Wed, 22 Feb 2006 01:38:23 -0600
"Gregg Vanderheiden" <gv@trace.wisc.edu> wrote:

> 
> 
> Here are some suggested edits for the WCAG Contrast guideline 
> Definitions
> 
> They are to clarify some ambiguous parts but do not change the guidelines.
> 
> 
> Gregg
> 
>  -- ------------------------------
> Gregg C Vanderheiden Ph.D. 
> Professor - Ind. Engr. & BioMed Engr.
> Director - Trace R & D Center
> University of Wisconsin-Madison
> The Player for my DSS sound file is at http://tinyurl.com/dho6b
> 
> 
> Note:  All modified content segments are enclosed in double braces 
> {{}}
> 
> 
> definition for "luminosity contrast ratio"
> 
> 
> [old definition...]
> 
> luminosity contrast ratio
> {{(L1+.05) / (L2+.05) where L is luminosity and is defined as .2126*R 
> + .7152*G + .0722B using linearized R, G, and B values. Linearized R 
> (for
> example) = (R/FS)^2.2 where FS is full scale value (255 for 8 bit 
> color channels). L1 is the higher value (of text or background) and L2 
> is the lower value.}}
> 
> [end of old definition]
> 
> 
> [new definition...]
> 
> luminosity contrast ratio
> {{(L1 + 0.05) / (L2 + 0.05), where L1 is the luminosity of the lighter 
> of the text and background colors, and L2 is the luminosity of the 
> darker of the text and background colors.
> 
> The luminosity of a color is defined as 0.2126 * ((R / FS) ^ 2.2) + 
> 0.7152 * ((G / FS) ^ 2.2) + 0.0722 * ((B / FS) ^ 2.2). R, G, and B are 
> the red, green, and blue RGB values of the color; FS is the maximum 
> possible full scale RGB value for R, G, and B (255 for eight bit color 
> channels); and the "^" character is the exponentiation operator.
> 
> Note: Luminosity values can range from 0 (black) to 1 (white), and 
> luminosity contrast ratios can range from 1 to 21.}}
> 
> [end of new definition]
> 
> 
> 
> 
> 

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--
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Received on Friday, 24 February 2006 15:10:26 GMT

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