- From: Jonathan Chetwynd <j.chetwynd@btinternet.com>
- Date: Tue, 16 Nov 2004 13:52:22 +0000
- To: "Will Pearson" <will-pearson@tiscali.co.uk>
- Cc: "SVG \(www\) list" <www-svg@w3.org>
Will, at this stage it's really important to gather evidence, so if you have examples, let's see them. traditional schemes such as white on black tend to be used for text. (where text flows over graphics this may not always be helpful) But do we have good examples of how illustrations and photographs can be made more accessible by changing contrast? my particular interest is symbols, so stroke width and opacity are options supplied. 2 examples: http://www.peepo.co.uk/launch/index.svg change settings using the hammer icon asv3 http://www.peepo.co.uk/style/contrast.svg switch style sheets mozSVG native RDF GUI schema should be helpful in defining what purpose the author intended the content for, which should help guide the user. for instance as a default, borders or highlights should probably be included in basic contrast changes such as white on black, whereas illustrations or jpegs should not. try: http://www.peepo.co.uk/temp/gui-schema OS systems may also offer some contrast controls. however the current mac beta complements all colours in white on black mode, which may not be that helpful. I use style sheets with classes as well as script sliders for finer user control. This seems to be forbidden in SVG, advice is not to try. there is further info on the svg-developers thread which may be helpful. regards Jonathan Chetwynd http://www.peepo.co.uk "It's easy to use" irc://freenode/accessibility On 16 Nov 2004, at 12:46, Will Pearson wrote: Hi Jonathan; What sort of levels of contrast would you have? Contrast is a really useful feature, and one I do think ua's should implement. I'm just wondering what your views on the best method for the user to select the contrast level would be? Generally, I tend to think default schemes, such as black on white, white on black, etc. are the easiest for users to use, but they don't cater for everyone. Some people may have preferences outside of those catered for by any default schemes, so maybe some advanced options to allow a user to select their own scheme would also be necessary. As an aside, I think user selectable color schemes are useful, not just user selectable contrast. I know that some dyslexics find changing the white background of text based documents, to another color, usually some shade of pink, enables them to read the document better. This has also been found to assist "normal" users in addition to those with dyslexia. Will ----- Original Message ----- From: "Jonathan Chetwynd" <j.chetwynd@btinternet.com> To: "SVG (www) list" <www-svg@w3.org> Cc: "chris Lilley" <chris@w3.org> Sent: Monday, November 15, 2004 7:00 PM Subject: Accessibility UAWG: contrast control > > Chris and members of the UAWG, > > it has been asserted by a number of people that a contrast control for > an SVG user agent is 'trivial' to implement*. > > UA and AT guidelines would without doubt encourage adoption of this and > other accessibility solutions. > Please could a draft be published? > > regards > > Jonathan Chetwynd > http://www.peepo.co.uk "It's easy to use" > irc://freenode/accessibility > > * 37 minute exchange: > http://svg.jibbering.com/svg/2004-11-15.html#T15-45-41 > > >
Received on Tuesday, 16 November 2004 13:52:55 UTC