RE: What is SVG?

Dear Anne,

I am not sure that this discussion belongs on the GL list, which is why I
wrote you privately earlier.  As I tried to explain, not all vector graphics
are created equal.  Yes, all vector graphics (including Flash) are
scaleable, but Flash does not use W3C SVG.  I will use the uppercase (SVG)
to refer specifically to the W3C markup standard.  The generic phrase
"scalable vector graphics" should not be confused with the W3C's open public
standard for said technology.

The SVG format is quite specific.  Flash and SVG have as little (and as
much) in common as do, for example, Windows BMP and PNG.  Yes, both are
means towards a similar end, but the implementation details are quite
different, with significant consequences.

SVG has a number of accessibility features.  Nothing like these has been
incorporated into other vector graphic formats (including Flash) although
one could are argue that the theoretical possible future potential is there.

At this point in time, SVG does require a viewer on most browsers.  This
will probably change in the near future.  SVG is not yet a final standard,
so I don't think complaints about this is warranted for now!  We are taking
about a technology which is still in development.

Besides the built-in the accessibility features, SVG offers a number of
advantages over other proprietary graphic formats (including Flash).  The
standard will be stable.  The standard is open to the public and derived by
consensus.  Properly done SVG images will at least present the integrated
textual equivalent if a viewer is not available.  The current and future
backwards compatibility is very high.

I am not an SVG expert, so I hope someone will correct anything that I've
said here which is blatantly wrong!  Has anyone seen a side-by-side
comparison of Flash to SVG?  I find it interesting that the MacroMedia site
says NOTHING about SVG.  I would have expected them to have information
(propaganda?) about why Flash is superior to SVG.  Are they really fairly
comparable?

Cheers,
Bruce Bailey


-----Original Message-----
From: w3c-wai-gl-request@w3.org [mailto:w3c-wai-gl-request@w3.org]On
Behalf Of Anne Pemberton
Sent: Wednesday, November 01, 2000 3:21 AM
To: Wendy A Chisholm; Web Content Accessibility Guidelines
Subject: Re: What is SVG?


Wendy and all,

Thanks to the many of you who have helped enlighten me. In twix moments
during the day, and during the assembly, I checked out most of what was
recommended. Wendy, your definitions were the final clinching ... 

I tried to download the viewer at school, but kept getting a "unavailable
page" message, but got it at home just a few minutes ago, and was finally
able to see something exciting in svg ... the clock on the adobe page. I
understand that the Flash, which I liked on that Lilly Frog page, may have
been vector graphics, perhaps svg ... which then makes me wonder why Flash
is still "inaccessible" if Flash graphics have all these assessibility
possibilities ...

For educational sites, I can see advantages of scalable graphics so that
the output can be sized as needed ... blown up to full page size, perhaps
larger, to print, full screen size, and if it can all be done from a
thumbnail sized file on the web, it's great! It could be a boon on sites
where you want the graphic to appear large on click ... The major drawback
is the fact that it's said not to do photos well yet ... A plus is that
graphics can be created into svg using at least two major graphics
softwares, Corel Draw and Adobe. 

A distinct downside is that you're back to that nasty mess of saying the
user has to download something in order to see what's on your site ... free
and fast is good ... but it still takes planning before the first use ...
and replacing everytime your system crashes and you have to re-load
everything you can remember you had ... (needless to say that I am well
acquainted with inadequate backup ... always two weeks out of date, and the
only free download I save is Eudora, none of the rest ... ) 

Thanks for your help, folks. I am seeing advantages to svg and a reason to
suggest it in the guidelines. But I think that the realities of the
limitations need to be there too. Perhaps as a sub-number under Guideline 3
... to define the graphics that can be done in vector graphics (at present,
free of bugs!) ... and those that will need to be in bitmaps ... the
techniques should tell what software needs to be used, and how to put the
"download free software option" on the page ... 

It is a bit disturbing that a special download is needed ... that may add
an "unnecessary" hardship on cognitively-disabled folks, who would benefit
from the scalability of the graphic ... 

					Anne

Received on Wednesday, 1 November 2000 11:50:21 UTC