Anonymizing and obfuscating PDF content while preserving document structure

Abstract

The portable document format (PDF) is both versatile and complex, with a specification exceeding well over a thousand pages. For independent developers writing software that reads, displays, or transforms PDFs, it is difficult to comprehensively account for all of the potential variations that might exist in the wild. Compounding this problem are the usage agreements that often accompany purchased and proprietary PDFs, preventing end users from uploading a troublesome document as part of a bug report and limiting the set of test cases that can be made public for open source development. In this paper, pdf-mangler is presented as a solution to this problem. The goal of pdf-mangler is to remove information in the form of text, images, and vector graphics while retaining as much of the document structure and general visual appearance as possible. The intention is for pdf-mangler to be deployed as part of an automated bug reporting tool for PDF software.