This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.

Bug 9747 - several bugs and comments on the draft from Jonathan Avila
Summary: several bugs and comments on the draft from Jonathan Avila
Status: RESOLVED FIXED
Alias: None
Product: HTML WG
Classification: Unclassified
Component: pre-LC1 alt techniques (editor: Steven Faulkner) (show other bugs)
Version: unspecified
Hardware: PC Windows NT
: P2 normal
Target Milestone: ---
Assignee: steve faulkner
QA Contact: HTML WG Bugzilla archive list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-05-17 14:34 UTC by steve faulkner
Modified: 2010-11-28 07:35 UTC (History)
5 users (show)

See Also:


Attachments

Description steve faulkner 2010-05-17 14:34:49 UTC
Steven, this document will be very useful to developers.  One user group
that I feel should be added under "Examples of scenarios where users
benefit from text alternatives for images" are users with visual
impairments who do not use screen readers or assistive technology.  This
includes users with color deficiencies and users with low vision.

This is important because many users with low vision may be able to read
the text and interpret most images but may need alternative text for
certain images.  When alt text is only displayed with the alt attribute,
users of some browsers and keyboard only users in this category will not
have access to this text.

In addition, related to example 4.1, using the alt attribute alone would
IMHO not be sufficient for WCAG 2 compliance because the alternative for
those who cannot distinguish colors is provided through the alt attribute.
If a person with color deficiencies with normal acuity were viewing this
image with a browser such as Firefox they would not have access to the
alternative text.

My recommendation in this latter example is to require that any meaning
conveyed in the image via color is in additionally displayed without the
use of color directly in the image (hatching, lines, etc.) or as text
visible on-screen.  The alt attribute does not suffice in these
situations.  I think this note would be a great addition to the document
that you are authoring.

jon.avila@ssbbartgroup.com
Comment 1 steve faulkner 2010-11-28 07:35:10 UTC
EDITOR'S RESPONSE: This is an Editor's Response to your comment. If you are
satisfied with this response, please change the state of this bug to CLOSED. If
you have additional information and would like the editor to reconsider, please
reopen this bug. If you would like to escalate the issue to the full HTML
Working Group, please add the TrackerRequest keyword to this bug, and suggest
title and text for the tracker issue; or you may create a tracker issue
yourself, if you are able to do so. For more details, see this document:
   http://dev.w3.org/html5/decision-policy/decision-policy.html

Status: partially accepted
Change Description: I will add text to the spec to warn against the siutaion you describe, I will also modify the images to ensure that there is sufficient contrast between the text abd the backgrounds in the images.

Rationale: the images include text that indicates the colours. So it is not colour alone that provides the colour information.