Fixing Bounding Box Failures (Simplified Editor)

Modified on Wed, 1 Jul at 4:11 PM

Issue

When validating a PDF for PDF/UA compliance in the Simplified Editor, you may receive a Failure on your Compliance Report indicating that one or more images do not have Bounding Box (BBox) attributes, or that the existing BBox values are incorrect.

A Bounding Box defines the exact position and dimensions of an object on a page, such as an image, table, or link. These attributes allow assistive technologies and PDF processors to accurately identify the location and size of tagged page elements.

Fixing this issue is not currently a Simplified Editor function. It requires opening the document in the Advanced Editor.

Symptom

The Compliance Report lists a failure related to an image's Bounding Box, similar to:

Image BBox attribute missing
Image Bounding Box not set
Image BBox incorrectly set

One or more images appear in the list of failed accessibility checks.

Causes

This issue typically occurs when:

An image was added or modified without updating its Bounding Box attributes.
The Bounding Box values became invalid during document editing or conversion.
A third-party application generated the PDF without properly calculating the BBox values.

Because the Bounding Box identifies an object's position and size, missing or incorrect values can prevent PDF/UA conformance.

Affected Users

Screen reader users, whose assistive technologies rely on properly tagged document structures.
Users of other assistive technologies that interpret tagged PDF content.

Accessibility Guidelines

PDF/UA-1 – Tagged objects, such as Figures, require appropriate attributes, including valid Bounding Box (BBox) information where required for conformance.

Resolution Steps

The Simplified Editor does not include a fixing option, so this issue must be resolved in the Advanced Editor.

Open the PDF in the Advanced Editor. (Re-upload or select "Edit again in Advanced Editor" from the Remediations menu.
Follow the steps in "Troubleshooting Verification Failure - Figure tag missing BBox attributes (Desktop and Advanced Editor)" to run the Fix Wizard and calculate the correct Bounding Box values.
Save the document.

You do not need prior Advanced Editor experience to complete this fix. It only requires the steps in the linked article.

Verification

After using the Advanced Editor to fix the issue, run the Verification check using the Advanced Editor. The issue has been successfully resolved when:

The Image BBox failure no longer appears in the Compliance Report.
The image passes PDF/UA validation.
No additional Bounding Box errors are reported after rerunning the accessibility checker.

Due to the Simplified Editor not having the ability to automatically solve Bounding Box issues, most related articles can be found when referencing the Advanced Editor.