- From: Jonathan Avila <jon.avila@ssbbartgroup.com>
- Date: Tue, 3 Nov 2015 20:24:59 +0000
- To: Shawn Henry <shawn@w3.org>, "public-low-vision-a11y-tf@w3.org" <public-low-vision-a11y-tf@w3.org>
> So this issue is not specific to low vision. The user requirement to turn off background images could also be an issue for users with cognitive disabilities. It's not really an issue for screen reader users though. The implementation is often an issue for screen reader users as supplying alt text for these images is not available in CSS3 so other techniques are used such as off-screen positioned text or aria-label, etc. But the solution and impact on design for users of screen readers and users with low vision is totally different. That is to solve the implementation for screen readers you add some programmatic text. For users who want background images turned off you have to make sure you replace the background image with other content that will fit within the area and is also accessible, e.g. svg as opposed to icon fonts, etc. That is the programmatic text is not surfaced by user agents and is often too large to fit into the area. Jonathan -- Jonathan Avila Chief Accessibility Officer SSB BART Group jon.avila@ssbbartgroup.com 703-637-8957 (o) Follow us: Facebook | Twitter | LinkedIn | Blog | Newsletter -----Original Message----- From: Shawn Henry [mailto:shawn@w3.org] Sent: Tuesday, November 03, 2015 3:01 PM To: public-low-vision-a11y-tf@w3.org Subject: Re: CSS background images and HCM [was: Low vision user requirements wiki page] Laura Carlson wrote: > WCAG has Technique F3: Failure of Success Criterion 1.1.1 due to using > CSS to include images that convey important information Right! Thanks for the reminder. So this issue is not specific to low vision. ~Shawn Laura Carlson wrote: > Hi Shawn, > > The fundamental user issue is that CSS background images in HCM vanish > and are not perceivable. > > It could potentially be solved by any of the 3. > > WCAG has Technique F3: Failure of Success Criterion 1.1.1 due to using > CSS to include images that convey important information > http://www.w3.org/TR/WCAG20-TECHS/F3.html > > Kindest Regards, > Laura > > On 10/28/15, Shawn Henry <shawn@w3.org> wrote: >> Re below: Is the fundamental issue that: >> 1. images that provide contextual information should not be included >> via CSS background? >> *or* >> 2. high contrast mode (HCM) and other setting should not turn off >> background images? >> *or* >> 3. users should have the option of turning background images on or >> off in HCM and other settings? >> *or* >> 4. other... >> >> >> >> On 10/28/2015 10:52 AM, Laura Carlson wrote: >>> Hi Shawn Jon, and all, >>> >>> Good catch, Jon. That is one of our use cases page. It is currently >>> the second point under color and contrast with the unique identifier >>> [Laura, UC-7] . >>> https://www.w3.org/WAI/GL/low-vision-a11y-tf/wiki/User_stories_-_use >>> _cases#Color_and_Contrast >>> >>> It might be good to include the unique identifier [Person, UC-#] >>> from the "User stories - use cases" on the user requirements table >>> for reference, mapping and to be sure we don't miss others, which >>> should be included. >> >> Done (after I post the up date :-). >> ~Shawn >> >>> >>> Thanks. >>> >>> Best Regards, >>> Laura >>> >>> On 10/28/15, Jonathan Avila <jon.avila@ssbbartgroup.com> wrote: >>>> Shawn, I wanted to discuss another potential item for the user >>>> requirements >>>> - what about removal of background/non-decorative images. That is >>>> a11y features such as High contrast in Windows will remove >>>> background images that are seen as decorative from the page >>>> content. This is an issue when background image techniques are >>>> incorrectly used by developers with meaningful images and then >>>> content is missing. If this is already covered - please excuse >>>> this note. >>>> >>>> Best Regards, >>>> >>>> Jonathan >>>> >>>> -- >>>> Jonathan Avila >>>> Chief Accessibility Officer >>>> SSB BART Group >>>> jon.avila@ssbbartgroup.com<mailto:jon.avila@ssbbartgroup.com> >>>> Phone 703.637.8957 >>>> Follow us: Facebook<http://www.facebook.com/#!/ssbbartgroup> | >>>> Twitter<http://twitter.com/#!/SSBBARTGroup> | >>>> LinkedIn<http://www.linkedin.com/company/355266?trk=tyah> | >>>> Blog<http://www.ssbbartgroup.com/blog> | >>>> Newsletter<http://eepurl.com/O5DP> >>>> >>>> >>> >>> >> >> > >
Received on Tuesday, 3 November 2015 20:25:32 UTC