Re: 48-Hour Call for Consensus (CfC): CSS Filters Comment Request

+1

On Wed, Dec 12, 2018, 5:25 PM Janina Sajka <janina@rednote.net wrote:

> Colleagues:
>
> This is a Call for Consensus (CfC) to the Accessible Platform
> Architectures (APA) Working Group on a proposed Accessibility
> Considerations Section request to the CSS Working Group.
>
> **Suggested Comment**
>
>  The Accessible Platform Architectures (APA) Working Group requests
> addition of the following section to the specification Filter Effects
> Module Level 1
> https://www.w3.org/TR/filter-effects-1/ <
> https://www.w3.org/TR/filter-effects-1/>
>
> Accessibility Considerations Statement
>
> In addition to standard WCAG 2.1 requirements for images, content authors
> using filter effects should be mindful of how the filters modify the
> colors, contrast, size, and animation of images.  The following Level A and
> AA success criteria could be affected:
>
> *Success Criterion 1.4.1 Use of Color (
> https://www.w3.org/TR/WCAG21/#use-of-color <
> https://www.w3.org/TR/WCAG21/#use-of-color>). Given a button shaped as an
> arrow with the text, “next,” a filter could modify the background color so
> that the text is no longer visible.
> *Success Criterion 1.4.3 Contrast (minimum)
> https://www.w3.org/TR/WCAG21/#contrast-minimum <
> https://www.w3.org/TR/WCAG21/#contrast-minimum>). Given the example
> above, a filter could modify the background or text color(s) so  color
> contrast requirement is not longer met.
> *Success Criterion 1.4.11 - Non-text Contrast (
> https://www.w3.org/TR/WCAG21/#non-text-contrast <
> https://www.w3.org/TR/WCAG21/#non-text-contrast>). Given the example
> above, a filter could modify the colors so that the contrast between the
> text and button color, and/or the button color and background no longer
> meet color contrast requirements.
>     It is particularly important to be mindful of color contrast
> requirements when a transparency is present because automated measurement
> is not available to quantitatively and correctly judge whether sufficient
> contrast is being provided, thus requiring application of informed human
> judgement on a case by case basis.
> *Success Criterion 2.3.1 Three Flashes or Below Threshold (
> https://www.w3.org/TR/WCAG21/#three-flashes-or-below-threshold <
> https://www.w3.org/TR/WCAG21/#three-flashes-or-below-threshold>)  Beware
> of any filters that add animation that may add or change the flash rate.
>
> *       ACTION TO TAKE
>
> This CfC is now open for objection, comment, as well as statements of
> support via email. Silence will be interpreted as support, though
> messages of support are certainly welcome.
>
> If you object to this proposed action, or have comments concerning this
> proposal, please respond by replying on list to this message no later
> than 23:59 (Midnight) Boston Time, Monday 17 December.
>
> NOTE: This Call for Consensus is being conducted in accordance with the
> APA Decision Policy published at:
>
> http://www.w3.org/WAI/APA/decision-policy
>
> Thanks to Becky Gibson for drafting this comment.
> http://lists.w3.org/Archives/Public/public-apa/2018Dec/0010.html
>
>
>
> ------------------------------------------------------------------------------
>
> Janina Sajka
>
> Linux Foundation Fellow
> Executive Chair, Accessibility Workgroup:       http://a11y.org
>
> The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
> Chair, Accessible Platform Architectures        http://www.w3.org/wai/apa
>
>
>