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Number of posts in this thread: 8 (In chronological order)

From: Leo Smith
Date: Thu, Sep 13 2001 7:58AM
Subject: client-side image maps
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Hi All,
Was wondering if anyone would like to comment on the
accessibility of client-side imagemaps. Section 508 specifies that
a client-side map should be used rather than a server-side one, and
that alt text should be provided for the image and for the hotspots.
W3C priority 3 checkpoint says "until user agents render text
equivalents for client-side image map links, provide redundant text
links for each active region of a client-side imagemap."
I am assuming this is referring to the fact that when images are
turned off in a browser (user agent), the alt text for the hotspots is
not displayed in the browser, but only the alt text for the imagemap
image. This is something that I have only just noticed.
Do most screen readers correctly read the alt text for the image
map hotspots on a client-side image map?
Also, rather than providing redundant text links for such an image
map (this could be a lengthy list depending on the size and extent
of the image map), what do folks think about using transparent gifs
instead, one for each link of the image map with appropriate alt
text? This would be read by a screen reader and display in
browsers with images off, but would not affect the visual layout of
the page with images on.
Thoughts? Comments?

Best,
Leo.
Leo Smith
Web Designer/Developer
USM Office of Publications and Marketing
University of Southern Maine
207-780-4774

From: Carol Foster
Date: Thu, Sep 13 2001 8:21AM
Subject: cleint-side image maps
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From: Michael Goddard
Date: Thu, Sep 13 2001 8:29AM
Subject: client-side image maps
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----- Original Message -----
From: "Leo Smith" < = EMAIL ADDRESS REMOVED = >
To: "WebAIM forum" < = EMAIL ADDRESS REMOVED = >
Sent: Thursday, September 13, 2001 9:54 AM
Subject: client-side imagemaps
> Also, rather than providing redundant text links for such

From: Leo Smith
Date: Thu, Sep 13 2001 2:55PM
Subject: image maps
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>Michael [ I do not see exactly how using transparent gifs would work in the
> scenario you are talking about. If a person disables images within
> their browser, then the transparent gifs would not be displayable
> either.]
Transparent gif's are invisible whether images are turned on or off,
hence the name transparent. The reason for having a transparent
gif for each link in the image map (as well as the image map) would
be so that alt text would display for each link when images are
turned off in the browsers. When images are turned off in a
browser, alt text for the individual hotspots (that is, alt text for each
<area> tag does NOT show - in IE and I imagine in other browsers
also, although I haven't had a chance to test the others). For alt
text for a transparent gif, the alt text would display with images off.
>Michael [ I feel the simpliest solution is to provide an "alt" description
> attribute within the <area> element/tag of the <map> element/tag. So
> even with the images turned off within the browser, the image map is
> still loaded within the browser and the area element is still
> available with the corresponding "alt" description attribute to help
> identify the hyperlink.]
No, this is not the case in IE. With images turned off, the individual
alt text for each <area> element does not show - only the alt text
for the imagemap image does. Hence, my initial email.

>Michael [ This is how I have the image map at
www.ohiogoodwills.org set up. So
> even with images turned off, the image map is still available with
> "alt" descriptions to identify everything.]
With images off in IE5, the alt text for your <area> elements in
your imagemap do not display.

Warmest regards to all also, in these very difficult times.
Leo.

Leo Smith
Web Designer/Developer
USM Office of Publications and Marketing
University of Southern Maine
207-780-4774

From: Michael Goddard
Date: Thu, Sep 13 2001 3:03PM
Subject: Re: image maps
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I still do not understand this! I know about transparent gifs etc..BUT and
a big BUT a transparent gif is STILL an image and if the browser is set to
not show images then why in the hell is it showing the transparent gifs?
Anyone care to enlighten me on that one!?
Hmm..It might be possibly the "title" that needs to be specified for the
<area> element. I will have to try this later to verify it.
Thank you for the information.
Michael
----- Original Message -----
From: "Leo Smith" < = EMAIL ADDRESS REMOVED = >
To: "WebAIM forum" < = EMAIL ADDRESS REMOVED = >
Sent: Thursday, September 13, 2001 4:51 PM
Subject: image maps

>
>
> >Michael [ I do not see exactly how using transparent gifs would work in
the
> > scenario you are talking about. If a person disables images within
> > their browser, then the transparent gifs would not be displayable
> > either.]
>
> Transparent gif's are invisible whether images are turned on or off,
> hence the name transparent. The reason for having a transparent
> gif for each link in the image map (as well as the image map) would
> be so that alt text would display for each link when images are
> turned off in the browsers. When images are turned off in a
> browser, alt text for the individual hotspots (that is, alt text for each
> <area> tag does NOT show - in IE and I imagine in other browsers
> also, although I haven't had a chance to test the others). For alt
> text for a transparent gif, the alt text would display with images off.
>
> >Michael [ I feel the simpliest solution is to provide an "alt"
description
> > attribute within the <area> element/tag of the <map> element/tag. So
> > even with the images turned off within the browser, the image map is
> > still loaded within the browser and the area element is still
> > available with the corresponding "alt" description attribute to help
> > identify the hyperlink.]
>
> No, this is not the case in IE. With images turned off, the individual
> alt text for each <area> element does not show - only the alt text
> for the imagemap image does. Hence, my initial email.
>
>
> >Michael [ This is how I have the image map at
> www.ohiogoodwills.org set up. So
> > even with images turned off, the image map is still available with
> > "alt" descriptions to identify everything.]
>
> With images off in IE5, the alt text for your <area> elements in
> your imagemap do not display.
>
>
>
> Warmest regards to all also, in these very difficult times.
>
> Leo.
>
>
>
> Leo Smith
> Web Designer/Developer
> USM Office of Publications and Marketing
> University of Southern Maine
> 207-780-4774
>
>

From: Leo Smith
Date: Mon, Sep 17 2001 6:30AM
Subject: image maps
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Michael,
I actually heard of this technique on a web developers listserv that I
belong to. As far as I understand it, I think this is how it goes:
As has been discussed, with images turned off in a browser, the alt
text or title text for each hotspot does not display - only the alt text
for the actual image used for the image map does. I am presuming
this is the reason for the W3C Priority 3 guideline saying to provide
redundant text links for each hotspot until browsers render the text
equivalents.
Instead of providing a set of visible redundant text links duplicating
each hotspot link, the transparent gif idea would be to have,
instead, transparent gifs duplicating the links. The gifs would
merely provide a placeholder for a duplication of each image map
link, with associated alt text for each gif describing which link each
gif was for. The actual gif image itself is irrelevant - it just acts as a
placeholder for the href and the alt text. Then with images off, the
alt text for these dupicate links WOULD be displayed by a browser.
As far as screen readers are concerned, as I understand it, most
readers will read alt text for the hotspots OK, whether images are
switched on or off in the browser. However, if a reader did not,
these gifs would also provide links and alt text that could be read
by a reader just like any image used as a link can be read be a
reader.
So, basicly, the transparent gifs are a way of invisibly providing the
redundant links that the priority specifies, except that they would
not be text ones, but image links. The advantages I can see from
going this route is that the page would not be cluttered with a group
of redundant text links (sometimes image maps can have a lot of
links), which might be confusing for those not requiring them.
Hope that makes sense...
Have a great week all!
Leo.
On 14 Sep 2001, at 14:14, WebAIM accessibility forum wrote:
> I still do not understand this! I know about transparent gifs
> etc..BUT and a big BUT a transparent gif is STILL an image and if the
> browser is set to not show images then why in the hell is it showing
> the transparent gifs? Anyone care to enlighten me on that one!?
>
> Hmm..It might be possibly the "title" that needs to be specified for
> the <area> element. I will have to try this later to verify it.
>
> Thank you for the information.
>
> Michael

Leo Smith
Web Designer/Developer
USM Office of Publications and Marketing
University of Southern Maine
207-780-4774

From: Michael Goddard
Date: Mon, Sep 17 2001 11:45AM
Subject: Re: image maps
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That is interesting! Would you happen to have a link or something relevant
so that I can look up more on this particular tip? I am confused on exactly
where you would place the transparent gif. Since physically 2 images cannot
occupy the same placeholder space??
Thank you for the information.
Michael
----- Original Message -----
From: "Leo Smith" < = EMAIL ADDRESS REMOVED = >
To: "WebAIM forum" < = EMAIL ADDRESS REMOVED = >
Sent: Monday, September 17, 2001 8:26 AM
Subject: image maps

> Michael,
>
> I actually heard of this technique on a web developers listserv that I
> belong to. As far as I understand it, I think this is how it goes:
>
> As has been discussed, with images turned off in a browser, the alt
> text or title text for each hotspot does not display - only the alt text
> for the actual image used for the image map does. I am presuming
> this is the reason for the W3C Priority 3 guideline saying to provide
> redundant text links for each hotspot until browsers render the text
> equivalents.
>
> Instead of providing a set of visible redundant text links duplicating
> each hotspot link, the transparent gif idea would be to have,
> instead, transparent gifs duplicating the links. The gifs would
> merely provide a placeholder for a duplication of each image map
> link, with associated alt text for each gif describing which link each
> gif was for. The actual gif image itself is irrelevant - it just acts as a
> placeholder for the href and the alt text. Then with images off, the
> alt text for these dupicate links WOULD be displayed by a browser.
>
> As far as screen readers are concerned, as I understand it, most
> readers will read alt text for the hotspots OK, whether images are
> switched on or off in the browser. However, if a reader did not,
> these gifs would also provide links and alt text that could be read
> by a reader just like any image used as a link can be read be a
> reader.
>
> So, basicly, the transparent gifs are a way of invisibly providing the
> redundant links that the priority specifies, except that they would
> not be text ones, but image links. The advantages I can see from
> going this route is that the page would not be cluttered with a group
> of redundant text links (sometimes image maps can have a lot of
> links), which might be confusing for those not requiring them.
>
> Hope that makes sense...
>
> Have a great week all!
>
> Leo.
>
> On 14 Sep 2001, at 14:14, WebAIM accessibility forum wrote:
>
> > I still do not understand this! I know about transparent gifs
> > etc..BUT and a big BUT a transparent gif is STILL an image and if the
> > browser is set to not show images then why in the hell is it showing
> > the transparent gifs? Anyone care to enlighten me on that one!?
> >
> > Hmm..It might be possibly the "title" that needs to be specified for
> > the <area> element. I will have to try this later to verify it.
> >
> > Thank you for the information.
> >
> > Michael
>
>
>
> Leo Smith
> Web Designer/Developer
> USM Office of Publications and Marketing
> University of Southern Maine
> 207-780-4774
>
>

From: Leo Smith
Date: Tue, Sep 18 2001 6:23AM
Subject: gifs and maps
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