Docling Document

With Docling v2, we introduce a unified document representation format called DoclingDocument. It is defined as a pydantic datatype, which can express several features common to documents, such as:

• Text, Tables, Pictures, and more
• Document hierarchy with sections and groups
• Disambiguation between main body and headers, footers (furniture)
• Layout information (i.e. bounding boxes) for all items, if available
• Provenance information

The definition of the Pydantic types is implemented in the module docling_core.types.doc, more details in source code definitions.

It also brings a set of document construction APIs to build up a DoclingDocument from scratch.

Example document structures

To illustrate the features of the DoclingDocument format, in the subsections below we consider the DoclingDocument converted from tests/data/word_sample.docx and we present some side-by-side comparisons, where the left side shows snippets from the converted document serialized as YAML and the right one shows the corresponding parts of the original MS Word.

Basic structure

A DoclingDocument exposes top-level fields for the document content, organized in two categories. The first category is the content items, which are stored in these fields:

• texts: All items that have a text representation (paragraph, section heading, equation, ...). Base class is TextItem.
• tables: All tables, type TableItem. Can carry structure annotations.
• pictures: All pictures, type PictureItem. Can carry structure annotations.
• key_value_items: All key-value items.

All of the above fields are lists and store items inheriting from the DocItem type. They can express different data structures depending on their type, and reference parents and children through JSON pointers.

The second category is content structure, which is encapsualted in:

• body: The root node of a tree-structure for the main document body
• furniture: The root node of a tree-structure for all items that don't belong into the body (headers, footers, ...)
• groups: A set of items that don't represent content, but act as containers for other content items (e.g. a list, a chapter)

All of the above fields are only storing NodeItem instances, which reference children and parents through JSON pointers.

The reading order of the document is encapsulated through the body tree and the order of children in each item in the tree.

Below example shows how all items in the first page are nested below the title item (#/texts/1).

Grouping

Below example shows how all items under the heading "Let's swim" (#/texts/5) are nested as chilrden. The children of "Let's swim" are both text items and groups, which contain the list elements. The group items are stored in the top-level groups field.