Figures need a bounding box

PDF/UA check FIGURE_BBOX · Figures & images · severity Medium · PDF/UA 8.2.6.2 Layout attributes

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Why it matters#

Assistive technology and reflow views use the bounding box to locate a figure on the page. PAC reports figures without a bounding box as 'Figure element without bounding box'.

What you will see#

A Figure has no BBox layout attribute. PAC reports this as "Figure element without bounding box".

How to fix#

Add a BBox entry in a Layout attribute object (O = Layout) on the Figure structure element, giving the figure's rectangle in page coordinates. Retagging the figure with Acrobat's Reading Order tool sets this automatically.

Step-by-step guide#

1. Easiest fix in Acrobat: open All tools > Prepare for accessibility > Fix reading order (the Reading Order tool), drag a selection around the figure's content on the page, and click Figure to retag it - Acrobat writes a Layout attribute object with a BBox for that region automatically.
2. Re-apply the figure's Alternate Text afterwards if retagging replaced the old tag (right-click the figure > Edit Alternate Text).
3. Outside Acrobat, a missing BBox means the producing application wrote the figure's layout attributes incompletely; regenerate the PDF from the source with a compliant tagged-PDF export. A correct figure carries a Layout attribute object: O = Layout plus a BBox array of four numbers (left, bottom, right, top) in page user-space coordinates enclosing all the figure's content.
4. At scale, retag the affected figures with the Reading Order tool page by page, or regenerate the document from its source - Acrobat has no supported dialog for authoring arbitrary attribute objects, so bulk fixes are most reliable at the source.

Verify: Re-run the EQChecker scan: FIGURE_BBOX should pass.

Note: ISO 14289-2 8.2.5.28 itself imposes no BBox requirement - it is a common validator expectation carried over from PDF/UA-1 practice and the general layout-attribute rule in 8.2.6.2, so EQChecker reports it at low severity. The BBox must enclose all of the figure's content on the page; a figure spanning pages cannot be described by one BBox and should be split per page.

WCAG success criteria#

No WCAG success criterion maps cleanly to this check — it is a PDF/UA structural requirement. The PDF/UA clause above is the normative reference.

Standards#

This check contributes to the following standards:

PDF/UA