RE: Comment on graphics contrast 680

Hi Jonathan,

So it doesn't affect PNGs, JPEGs etc?

That would be very good for making this point... thanks.

-Alastair

-----Original Message-----
From: Jonathan Avila [mailto:jon.avila@levelaccess.com] 
Sent: 14 January 2018 23:50
To: Alastair Campbell <acampbell@nomensa.com>; public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
Subject: RE: Comment on graphics contrast 680

Windows high contrast mode does not change the appearance of graphics in IE, FF, or Edge in my experience.  From what I recall Edge will keep background images but make text overtop of them easy to see.

Turning on high contrast mode in Windows would change borders of controls and focus indicators and selection colors that are part of native controls like combo box and input.  Users can specify colors for each type of thing, background, text color, window color, etc.  It would also change some other borders such as borders on divs to a single color.

On Chrome browser with Windows no effects are found with high contrast although there is a high contrast filter for Chrome.  In many cases it makes all content darker including images and can actually make some text less contrast.

On Mac (tested with Safari) the high contrast mode seems to increase the contrast of borders, focus, and some lines in native controls only IMO.  If I'd have to guess it might increase it to 7:1.   I noticed increased contrast on input border that was not styled and on spinner buttons.  So effects is limited to standard controls where colors are not set.  If an author settings a low contrast border the high contrast setting does not increase the contrast.

Jonathan 

Jonathan Avila
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Level Access, inc. (formerly SSB BART Group, inc.)
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-----Original Message-----
From: Alastair Campbell [mailto:acampbell@nomensa.com] 
Sent: Sunday, January 14, 2018 11:04 AM
To: public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
Subject: Comment on graphics contrast 680

Hi everyone,

I could do with some help for this comment:
https://github.com/w3c/wcag21/issues/680 

The cross-tester aspect I can deal with, but for this bit:
" we believe it is reasonable to assume that users in need of higher contrast in graphics would also need the same higher contrast when they are not using the web. It stands to reason that high contrast theme or similar OS accessibility features should already be in use. With high-contrast (or equivalent) turned on, the test result would likely be different."

My question is: How well do higher-contrast OS settings help with online graphics?

I had assumed that the contrast was relative, and turning it up at the OS level wouldn't really help with things like charts or icons on websites.

Does anyone have personal experience with this, or know whether it logically stacks up?

Thanks,

-Alastair

Received on Monday, 15 January 2018 00:25:45 UTC