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RE: high contrast and background images

From: Thierry Koblentz <ng@tjkdesign.com>
Date: Mon, 14 Jun 2010 18:10:49 -0700
To: "'Chris Reeve'" <chrisreeve15@yahoo.com>, "'Jonathan Avila'" <jon.avila@ssbbartgroup.com>, <w3c-wai-ig@w3.org>
Message-ID: <055701cb0c27$99266800$cb733800$@com>
H67 is related to decorative images, so high-contrast settings would not be an issue.

As a side note, there is no such thing as alt text for background images, and H67 does not say to not use alt, it says to use it with a null value (“”).

 

--

Regards,

Thierry

www.tjkdesign.com |  <http://www.ez-css.org> www.ez-css.org | @thierrykoblentz

 

From: Chris Reeve [mailto:chrisreeve15@yahoo.com] 
Sent: Monday, June 14, 2010 5:06 PM
To: ng@tjkdesign.com; Jonathan Avila; w3c-wai-ig@w3.org
Subject: Re: high contrast and background images

 

Another possibility I thought of is to choose a background image that can satisfy http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/H67

If the chosen background image satisfies H67, than there would not be any need for the alt tag.

 

  _____  

From: Thierry Koblentz <ng@tjkdesign.com>
To: Jonathan Avila <jon.avila@ssbbartgroup.com>; w3c-wai-ig@w3.org
Sent: Mon, June 14, 2010 3:51:08 PM
Subject: RE: high contrast and background images

> The technique developers need to use will allow this text to appear in
place of the background image when high contrast is used.

A better approach would be to *not* use a technique that relies on
background-image to avoid losing these images when users switch to high
contrast styles sheets. 

For example, a technique like this one should make this a non-issue:

http://tjkdesign.com/articles/how-to_use_sprites_with_my_Image_Replacement_t
echnique.asp

--
Regards,
Thierry
www.tjkdesign.com <http://www.tjkdesign.com/>  | www.ez-css.org <http://www.ez-css.org/>  | @thierrykoblentz

From: w3c-wai-ig-request@w3.org [mailto:w3c-wai-ig-request@w3.org] On Behalf
Of Jonathan Avila
Sent: Monday, June 14, 2010 11:19 AM
To: w3c-wai-ig@w3.org
Subject: RE: high contrast and background images

Chris Reeve Wrote:
“Cindy, I do not know enough about what Roger is talking about. But I do
know, that when you use a background image; it is impossible to use an alt
tag. Therefore by default; all alt background images will fail 1.1.1
 
This information came to me from an accessibility seminar I attended last
year.”
 
CSS background sprites are used to reduce the number of image files
transferred and thus speed of page load times for many users.  A small
portion of a background image can more easily be shown in a certain element
and thus a single background image can contain many of the images to be
shown on the page. There are many good techniques out there to couple text
and alternative text to the area where the background image appears.  The
technique developers need to use will allow this text to appear in place of
the background image when high contrast is used.
 
Jonathan



 
Received on Tuesday, 15 June 2010 01:11:15 GMT

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