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Re: WCAG 2and high contrast

for

From: Jonathan Avila
Date: Oct 5, 2015 7:09PM

> Windows High Contrast mode should not hide any images that are part of focusable elements. Or if Win HCM does hide the image then it should display the

I'd say that is easier said than done. Replacing the image with text may not fit into the space allocated and extending the space could have unforeseen consequences in pages that are not fluid. Keeping the background image goes against the whole idea -- background images should not convey meaning and they are often very problematic for low vision users -- how is the OS supposed to know if the author intended the image to be a decorative background image or a meaningful background image.

> I would say it's a bug in Windows High Contrast Mode if it hides a focusable element's image without displaying the accessible name of the element. No other high contrast modes hide background images, e.g. OS X/iOS high contrast modes and ZoomText Screen Magnifier don't do this.

Mac and iOS IMO don't have a true high contrast mode -- they have an invert colors mode -- and yuck it's not something I want to use unless I have no other option. Inverting colors changes inline images and makes the images very unpleasant and harder to visually decipher. The invert colors only really provides -- well one option -- the opposite of what was there -- that often but not always a single high contrast option. Windows high contrast mode on the other hand replaces foreground, background, and other control specific colors with user specified or pre-defined high contrast options. That is the Windows high contrast mode is customizable allowing the user to say what colors they want to see in high contrast -- perhaps that's black on white or green on white and inline images stay the way they were created -- except for the transparent parts. Users can specify colors for selection, borders, links, and all sorts of things in the OS.

So I disagree with those people who say Windows HC mode has a bug and should display background images -- background images -- are well background images and thus not content images and thus should be removed to assist users with low vision in reading page content. It really sounds like we need a CSS content image property that works and is supported and then developers can say this is a content image and this is a background image and then user agents can correctly hide or display the image per its purpose. Perhaps the current content and alt CSS properties are moving this direction.


Jonathan

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Jonathan Avila
Chief Accessibility Officer
SSB BART Group
<EMAIL REMOVED>

703-637-8957 (o)
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