- From: Loretta Guarino Reid <lguarino@adobe.com>
- Date: Thu, 24 Apr 2003 12:45:23 -0700
- To: Joe Clark <joeclark@joeclark.org>
- cc: WAI-GL <w3c-wai-gl@w3.org>
Joe,
I've appended the current draft of Checkpoint 1.5. Only when we get to Level
3 does the checkpoint "ban" text content over background images. At Level 1,
it is sufficient if your User Agent lets you control the display of the
background image.
The largest problem with text over background images isn't that the author
designed it with poor contrast in the first place (although colorblindness
considerations can make this more of a challenge). But when a user needs to
configure the text and background colors, the configured text color may no
longer provides sufficient contrast with the background image. This checkpoint
is trying to make it possible for that class of users to read the text.
Loretta
Checkpoint 1.5 Ensure that foreground content is easily differentiable from
background for both auditory and visual presentations.
Success criteria
You will have successfully met Checkpoint 1.5 at the Minimum Level if:
1.text content that is presented over a background image or pattern is
implemented using mechanisms that allow the user to display the text without
the background image or pattern.
You will have successfully met Checkpoint 1.5 at Level 2 if:
1.when text content is presented over a background image or pattern, the text
is easily readable when the page is viewed in 256 grayscale.
You will have successfully met Checkpoint 1.5 at Level 3 if:
1.text content is not presented over a background image or pattern OR the
text is easily readable when the page is viewed in black and white (no
grayscale).
2.audio content does not contain background sounds OR the background sounds
are at least 20 db lower than the foreground audio content.
3.text content is not presented over a background image or color OR the
colors used for the text and background or background image pass the following
test (from Techniques For Accessibility Evaluation And Repair Tools, dated
April 26, 2000): <<details of the test omitted>>
Received on Thursday, 24 April 2003 15:45:47 UTC