Re: Graphics Contrast responses

Hi Andrew,

If it helps, these are the graphics non-text contrast issues & draft responses:

282 – (From GreggV)

(AlastairC) Thank you for your comment. Since your comment was logged the SC has changed significantly. Relevant changes include: The combination of concepts for 'Graphical Objects' and 'Required for understanding' which allow for a more granular testing approach, and they allow for small overlaps. It means there are many more options in terms of colours and design options. Also, the level of contrast has been reduced to 3:1 across situations. There are examples included in the understanding document, and more will be added.

The Low vision task force has consulted with several researchers in the area, and while there is little direct research, their view was that the contrast level should be similar to reading text. However, for simplicity and feasibility the TF accepted the reduction to 3:1.

411 - (from kerstinp)

(AlastairC) Thank you for your comment. The term graphical object was selected to be generic as it covers a wide range of parts of graphics. Defining the term object (beyond the current text or the dictionary definition) does not appear to help. However, the Understanding document does include a large section to provide context and examples, and that is being expanded.

616 – (from karlgroves)

(AWK) The Working Group made the decision to not modify existing SC from WCAG 2.0, which is why these requirements are in a new SC. If you have any suggestions for an SC title that would address your concerns, please suggest it.

From the suggestions in the thread, "Non-text contrast" got the most support. As a term it is wider in scope than the criteria itself, but it aligns with WCAG 2.0 reasonably well. That change has been made in a new draft.

649 -  (from karlgroves)

(AlastairC) Thank you for your comment. The working group appreciates that the changes between states should be obvious to people viewing the content. However, it is very difficult to craft a requirement that does not run into the issue of not having enough colours for a particular component. The focus of this success criteria is to cover the non-text parts of (active) UI components, but we will certainly consider expanding to explicitly cover the differentiation of states for UI components in future iterations.

680 – (from

(From AlastairC): Thank you for your comment, as a member of the working group we assume there is no need to outline the CR process. Every SC should be tested, thank you for offering that support.

Regarding high contrast mode, from some initial testing neither Windows (10 + Edge) or OSX (+Safari) help with perceiving graphics embedded into web pages, which highlights the importance of that part of this SC even more.

Using a high-contrast mode could assist with the user-interface controls, but would be limited to standard controls, not custom ones created by authors.

If there are user-agent factors that haven't been considered, please do comment on how those might impact the SC. However, it is worth nothing that the requirement from the Low Vision Task Force was that it should be a minimum standard for those without user-agent /OS support for contrast.

686 - (from jasonjgw)

(AlastairC) Thank you for your comment, the group agrees we should test where "graphics are reused in a multiplicity of contexts", do you have any examples you could share? The group appreciates that context is important for images, and that can change between pages. However, in order to meet the user-need it must focus on what is required for understanding. Utilising that concept also makes it more feasible to implement in general scenarios, as it is a wider exemption that pure-decoration.



Received on Wednesday, 17 January 2018 17:58:37 UTC