- From: Charles McCathieNevile <charles@w3.org>
- Date: Mon, 17 Jun 2002 05:30:30 -0400 (EDT)
- To: Alan Chuter <achuter@teleservicios.com>
- cc: <w3c-wai-ig@w3.org>
To test this particular checkpoint I use lynx to view the content - since it
doesn't support colours or images it gives me a pretty good idea of several
things at once. To check whether images themselves rely on colour to convey
information I just look at them, or I drop my screen colours and contrast to
almost nothing. (I used to use CloseView - the magnification utility that was
always built into the Macintosh which could make everything black on white,
but unfortunately in their wisdom Apple haven't yet seen the need to provide
it in OS X).
Having to test this screen by screen through an image editor seems
frustrating, but does work well.
cheers
Chaals
On Mon, 17 Jun 2002, Alan Chuter wrote:
This is so obvious that I can't think that nobody has thought of it before.
The
WCAG techniques suggest:
"To test whether color contrast is sufficient to be read by people with
color
deficiencies or by those with low resolution monitors, print pages on a
black
and white printer (with backgrounds and colors appearing in grayscale)."
As many people have pointed out printing is not sufficient as the browser
compensates
for color problems. Using a B&W monitor it's awkward to compare between
monitors.
A simple solution is as follows. My example uses Windows and Microsoft
Office Photo
Editor but it will work with other platforms and editors I think.
1. Use Ctrl+Alt+PrintScreen to copy the image of the browser window
to the clipboard.
2. In Photo Editor, select Edit/Paste as new Image
3. Select File/Properties/Image/Type and switch to grayscale
4. Repeat step 2
You now have two copies of the window, one with color and one in grayscale,
and you
can toggle between them with Ctrl+F6 to compare.
Alan Chuter
achuter@teleservicios.com
Fundosa Teleservicios (ONCE Foundation), Madrid, Spain
ONCE (Spanish National Organization of the Blind)
--
Charles McCathieNevile http://www.w3.org/People/Charles phone: +61 409 134 136
W3C Web Accessibility Initiative http://www.w3.org/WAI fax: +33 4 92 38 78 22
Location: 21 Mitchell street FOOTSCRAY Vic 3011, Australia
(or W3C INRIA, Route des Lucioles, BP 93, 06902 Sophia Antipolis Cedex, France)
Received on Monday, 17 June 2002 05:30:41 UTC