- From: Leonard R. Kasday <kasday@acm.org>
- Date: Wed, 20 Dec 2000 15:45:42 -0500
- To: Kynn Bartlett <kynn-edapta@idyllmtn.com>, "Bailey, Bruce" <Bruce_Bailey@ed.gov>
- Cc: "'w3c-wai-gl@w3.org'" <w3c-wai-gl@w3.org>
Although I welcome the accessibility potential of SVG, I want to underline something that I perhaps skimmed by in earlier email. SVG can't handle all "styles" while keep text as the contents of the <text> element. For example, example 4 at http://astro.temple.edu/~kasday/wai/texteg/ (that's a raster image BTY, not SVG) shows a worm threaded through the letters of the word "Return". Here, the "style" is the threaded worm. That's going to be a problem for someone who has any type of low vision that forces him or her to use peripheral vision (e.g. a central scotoma). Magnification would be of limited use in that case. You'd want the user to have a style that omits the worm. Now, this picture can of course be represented as SVG. But as far as I can see, SVG has no way to keep the word "Return" as the contents of the <text> element and still show this effect. So I see no way strip out the worm style. In other words, it's just as bad as a raster image for at least some users. Also, this is worse than simply having some other style of font, like the "chilly" font I've spoken of earlier. SVG can handle differernt fonts via it's alternate glyph capability. So in principle, a user agent could go to standard font instead of the special glyphs. But worming text is more than just another font. (unless you constrain the worm to always enter and leave at the same height, which is not what I've done). So even with SVG, there will be situations where textual equivalents are needed. True, you may feel that this is a wierd, unlikely case. And if SVG adds some semantics like those of VRML, which allows letters to be treated as individual 3-D objects, it will be able to handle wormed text. But the problem is, no matter how many effects we give graphic artists in CSS or SVG, they will always strive to come up with something unique: and "unique", by definition, will be tend to be something that is not one of the canned effects (font, color, weight, distort, convolute etc) that are built into the language. That being said, I think SVG can potentially help a lot. I'm just saying we'll always have to consider cases where we can't separate style from content (unless we go to the underlying data of course). Len At 10:09 AM 12/20/00 -0800, Kynn Bartlett wrote: >At 05:55 AM 12/20/2000 , Bailey, Bruce wrote: > >Kynn, > >Assuming you're doing this on a windoze IE machine... > >Right click on the image, select "zoom-in" from the pop-up palette. Repeat > >as desired. Pretty cool, no? > >I am not sure how one would increase the canvas size. > >Wait, I'm confused. > >If someone uses SVG for navigation on their site -- say, as >navigation buttons containing textual information -- they have >to right-click on each image and choose "zoom in" to blow up >the image, but it is still constrained by the size of the >original graphic?? > >That's not at _all_ what I was hoping for. I was hoping for >the benefits described by members of this list, which state that >this is a boon to accessibility by people who have low vision. > >I have not seen anything to that effect, and in fact it's pretty >useless for such a purpose! I can't imagine why you'd have to >right-click on every single graphic on a page in order to see >it correctly (but in a tiny "window" space!) -- shouldn't it resize >according to my browser text size preferences?? > >I can only assume that I've done something very wrong in how I have >installed SVG support in my browser, as none of the supposed >benefits of SVG are evident to me. I can't imagine anyone claiming >_this_ as an accessibility benefit, so I guess I screwed up somewhere! > >--Kynn > >-- >Kynn Bartlett <kynn@idyllmtn.com> http://kynn.com/ >Director of Accessibility, Edapta http://www.edapta.com/ >Chief Technologist, Idyll Mountain Internet http://www.idyllmtn.com/ >AWARE Center Director http://www.awarecenter.org/ >What's on my bookshelf? http://kynn.com/books/ -- Leonard R. Kasday, Ph.D. Institute on Disabilities/UAP and Dept. of Electrical Engineering at Temple University (215) 204-2247 (voice) (800) 750-7428 (TTY) http://astro.temple.edu/~kasday mailto:kasday@acm.org Chair, W3C Web Accessibility Initiative Evaluation and Repair Tools Group http://www.w3.org/WAI/ER/IG/ The WAVE web page accessibility evaluation assistant: http://www.temple.edu/inst_disabilities/piat/wave/
Received on Wednesday, 20 December 2000 15:46:26 UTC