extract-struct-tree-ignored

All codes

• Type: warning
• Kind: input (a problem with the PDF file)

What happened

The page is tagged, but its structure tree didn’t pass the checks that decide whether to trust it, so extraction read the page in layout order instead.

Why

A structure tree gives a page’s reading order, but trees are often incomplete or wrong. Extraction uses a page’s tree only when its elements cover at least 80% of the page’s visible text, not counting headers, page numbers and other text the file marks as page furniture. Its order must also jump back up into an earlier column at most once in ten moves from block to block. A tree written by a tool that tags only some of the text, or that tags it in drawing order, fails one of the checks.

How to fix

Nothing to do: the page reads in layout order, as an untagged page would. To use the tree anyway, extract with ReadingOrder::Tagged (readingOrder: "tagged"). Like every warning, it fails the call in strict mode.

Example

A report whose tool tagged only its headings: the tree covers a tenth of the text, so the reason is coverage.

Data fields

• reason: coverage or order, the check that failed.

The location has the page’s pageIndex.