1. Images

The New Zealand government agency web site Standards related to using Images on web sites are:

1.1 Alternative text for every non-text element

Provide alternative text for every non-text element, such that it conveys the same meaning or information that the non-text element conveys (for example “alt”, “longdesc”, or in element content). This includes: images, graphical representations of text (including symbols), image map regions, animations (for example, animated GIFs), applets and programmatic objects, ASCII art, frames, scripts, images used as list bullets, spacers, graphical buttons, sounds (played with or without user interaction), stand-alone audio files, audio tracks of video, and video.

Guide to this standard

• A null Alt equivalent (“”) is required for layout elements e.g spacer graphics.
• For images, include in each <area> of an image MAP, and INPUT elements of type=”image”.
• Alt text for the case where the image is displaying text should be the same as the text in the image.

This standard covers the W3C WAI checkpoint 1.1 for NZ government agencies.

Compliance assistance

"Bobby" is an automated testing tool, which can tell you if images on a web page have Alt text associated with them.

Rationale for this standard

Users with visual impairments may have difficulty with content other than text. Screen readers will make use of the alt-text provided for non-text items.

1.2 Client side image maps preferred over server side image maps

Client side image maps are preferred over server side image maps. You must also provide redundant text links for each active region of any image map, and locate the links as close as possible to the image map they relate to.

Guide to this standard

Client side image maps are preferred over server side. However:

If server-side image maps must be used, then

• offer a text alternative to the server side map regions, or "hotpoints", at an appropriate place on the form (such as the form footer).
• The text alternative must have a mechanism to be able to be navigated to and selected without a mouse or equivalent device (i.e. able to be tabbed to and selected).
• Use the HTML alt text to enable this link, for example:
  <img src="../images/header_nav.gif" alt="SSC Main Menu(links of this image map are available at the bottom of the page)" ismap>

If client-side image maps are used, then

• Ensure there is an alt text, for example:
  <area shape="rect" coords="9,6,79,68" href="http:// www.ssc.govt.nz" alt="SSC Website">

This standard covers the W3C WAI checkpoints 1.2 and 1.5 for NZ government agencies.

Rationale for this standard

• Server-side image maps do not provide adequate support for alt text nor for conventional pointing devices (i.e. a mouse).
• People with cognitive or visual disabilities and/or those who do not have a “pointing device” (i.e. mouse) may require alternative methods for navigating and selecting their choices available on the site.

1.3 Text description of visual track of a multimedia presentation

Until user agents can automatically read aloud the text equivalent of a visual track, provide a text description [that can then be read] of the important information of the visual track of a multimedia presentation.

Guide to this standard

To assist understanding of this requirement, an analogy is a Karaoke machine. If video with the music has someone singing the track, the lyrics presented in written form on the screen are expected to be in sync with the music and the lip movements of the singer(s).

Provide a text equivalent or alternative, and an audio track to accompany a multimedia presentation, which describes important information presented in the visual track.

If possible, attempt to have the text and/or audio track synchronised with the presentation.

This standard covers the W3C WAI checkpoints 1.3 and 1.4 for NZ government agencies.

Rationale for this standard

There is a two-fold purpose for this standard.

• If information is provided primarily in multimedia clips i.e., scenery, charts etc., then the conveyance of the information will be lost to users with visual impairments.
• Having a written description (as opposed to recorded description) enables the text to be indexed and searched, which (at the time of writing) is extremely difficult with information contained within a multimedia clip.