W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > July to September 2003

Re: Possible problem with Fahrner Image Replacement

From: Brandon Bowersox <brandon@ojctech.com>
Date: Tue, 15 Jul 2003 10:09:02 -0500
Message-Id: <5.2.0.9.0.20030715095213.00bac638@10.2.2.195>
To: Joe Clark <joeclark@joeclark.org>, WAI-IG <w3c-wai-ig@w3.org>

Thanks for organizing this testing--I look forward to the results and the 
possibility that designers can use images to control the display of text 
without hindering accessibility.

One question--it seems there are 4 main problems with the age-old method of 
using images to display text:
1) The text will only be accessible if the designer includes useful ALT 
text within the IMG tag.
2) Even so, text inside an IMG ALT tag is not indexed by search engines and 
not searchable by users with a browser's Find feature.
3) Adding ALT text is not sufficient for AREAs inside a client-side 
imageMAP (redundant text should be added 
http://www.w3.org/TR/WCAG10-HTML-TECHS/#client-side-redundant-text)
4) Images with ALT text are not legible for low-vision users because the 
text is not crisp as it scales larger (even with the fancy zooming Opera does).

It seems to me that this CSS image replacement technique addresses 
#2.  This is a big step forward.  But I want to confirm that this technique 
may not address #1 (since it still relies heavily on useful text and effort 
from the page author) and #4 (since the screen CSS will be used and the 
replacement image, not the original text, will appear for low-vision users 
who read pages by zooming).

Maybe with some work we could make the technique helpful for situation 
#3--we could use blocks of SPANs that stack together and contain text which 
a screen-only CSS would replace with images.  The images would fit together 
to create the larger image and we would be in a sense doing a client-side 
imagemap without MAP and AREA.  All the regions would have to be 
rectangles, however, since we have no way of making a SPAN or DIV that 
would be non-rectangular to replace the AREA SHAPE="circle" or AREA 
SHAPE="poly".  (I hope this short explanation is clear).

Do you and others agree that this technique might not help with #1 and #4?

Brandon

At 10:26 PM 7/14/2003 -0400, Joe Clark wrote:

>Fahrner Image Replacement, named after Todd Fahrner (but apparently 
>invented by C.Z. Robertson), is a standards-compliant technique that uses 
>stylesheets to provide a visible image, usually of nicely-typeset words, 
>that is backed up by marked-up plain text. All the hip kids are using it.
>
><http://www.stopdesign.com/articles/css/replace-text/>
><http://rtnl.org.uk/words/19990709-site_updates.shtml>
><http://lists.w3.org/Archives/Public/w3c-wai-ig/2003JanMar/0870.html>
>
>Back in March, I had people try FIR in Window-Eyes and Home Page Reader, 
>and two of the test pages at 
><http://www.stopdesign.com/log/default.asp?date=20030314> read correctly. 
>I suppose it is a problem that all three did not.
>
>There is, however, the problem that screen readers are yoked to visual 
>browsers and inherit their stylesheet interpretations. {display: none} 
>really means {display: none}, and the treatment of visibility: hidden is 
>unclear.
>
>The result?
>
>One correspondent, using HPR on his machine, says that text marked up as 
>FIR disappears completely because it isn't an img element with alt; also, 
>{display: none} takes it out of the reading order altogether.
>
>You can test this on my new, all-CSS page for Ten Years Ago in _Spy_, 
>fixed up by Matt Mullenweg:
>
><http://www.fawny.org/spy/?FIR>
><http://photomatt.net/p722>
>
>WHAT I NEED:
>I need people to throw every screen reader they've got at that simple page 
><http://www.fawny.org/spy/?FIR> and see if you can read the text embedded 
>in graphics. There are two separate blocks, and I'm not gonna tell you 
>what they say-- the purpose is to see if you can read them.
>
>Use all screen readers you have, *especially Jaws*, though I doubt anyone 
>from Freedom Scientific would bother looking into this.
>
>Report back to me and I will summarize to the lists.
>
>If this technique is really not working, then the most advanced 
>standards-compliant sites designed by the most conscientious people at 
>work today have a serious problem-- one of the problems they were going 
>very much out of their way to avoid.
>
>--
>
>     Joe Clark | joeclark@joeclark.org
>     Accessibility <http://joeclark.org/access/>
>     Author, _Building Accessible Websites_
>     <http://joeclark.org/book/>
Received on Tuesday, 15 July 2003 11:09:10 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 19 July 2011 18:14:10 GMT