Introduction to PDF Collaboration Engine


PDF Collaboration Engine is a server-based command-line application that provides access to Annotation objects found in PDF documents.

It is designed to run in tandem with other processes in an unattended environment able to handle high-volume and on-demand production needs.

A copy of Adobe® Acrobat® is not needed in order for application to work, but a PDF viewer capable of rendering Annotations is required to view output PDF files.

PDF Annotations

Annotations are one of the PDF object types.  They are interactive fields, text, simple drawings, links, stamps, media attachments, and review marks added by users to an existing PDF file.  Adobe® Acrobat®, Adobe® Reader, and other PDF-rendering applications have tools that allow GUI placement, editing, and removal of most subtypes of Annotations.

One can imagine Annotations as writing, drawings, or media placed on a transparency over a document page.  This “transparency” may be stored, “Saved”, with the PDF document, or in a separate file – “exported” – and shared with other collaboration partners working on the same Document.  And because PDF Annotations have well-defined internal structure, it is possible to import, export, and manipulate them with a non-interactive, command-line application.  This is what PDF Collaboration Engine does.

Annotations Subtypes and pdfCE

Not all Annotations are treated equally by PDF Collaboration Engine.  It distinguishes between Commenting markup Annotations, or Comments, which are processed by default; and AcroForm fields and the rest of the subtypes, which require additional options ( see Features ) to be included in the output.  Appligent’s own registered Annotation subtype – DGAP:RedaxBox – and one of the oldest PDF subtypes – Link – are processed by default.




PDF Collaboration Engine Export

Subtype Description Markup? Has Popup? classification by default with -aa flag
Text Sticky notes, Checkmarks ( status ) Yes Yes Comments Yes Yes
Link URL, URI, or anchor link No No Media Yes Yes
FreeText Callout, Typewriter ( click-to-type ), TextBox Yes No Comments Yes Yes
Line One segment of a straight line Yes Yes Drawing markup Yes
Square Closed rectangle Yes Yes Drawing markup Yes
Circle Closed circle or eclips Yes Yes Drawing markup Yes
Polygon Polygon, Cloud Yes Yes Drawing markup Yes
PolyLine Polyline, multiple connected line segments Yes Yes Drawing markup Yes
Highlight Highlight Yes Yes Comments Yes Yes
Underline Underline Yes Yes Comments Yes Yes
Squiggly Squiggly-underline Yes Yes Comments Yes Yes
StrikeOut Strikeout / Cross-out Yes Yes Comments Yes Yes
Caret Text insertion mark Yes Yes Comments Yes
Stamp Rubber stamp, image, or snapshot Yes Yes Page markup Yes
Ink Freehand with Pencil and Eraser Yes Yes Page markup Yes
Popup Pop-up, an interactive part of other Annotations No * Comments Yes Yes
FileAttachment File attachment Yes Yes Media Yes
Sound Audio clip Yes Yes Media Yes
Widget An umbrella subtype for AcroForm fields No No Form fields with fields Yes
Redact Adobe redaction box, rectangle Yes Yes Page markup Yes
DGAP:RedaxBox Appligent’s Redax box Yes No Page markup Yes Yes