QualityLogic’s white paper, “Effective PDF Testing Strategy,” presents an effective testing methodology for PDF printers and applications. It includes a discussion of some of the most common misunderstandings, including how testing with only PDF files that are produced by common applications can be risky. Here are the main topics covered:

  • Introduction to PDF
  • Overview of Interoperability Testing
  • Overview of Conformance Testing
    • Explanation of PDF coverage from Office Word 2007 application
    • Explanation of PDF coverage from QualityLogic PDF Functional Test Suite
    • Examples of real problems uncovered by PDF FTS in real PDF printers and viewers
  • Use of TestJob Builder in Testing in conjunction with test suites
  • Customer Testimonials
  • Recommendations of Testing Strategy for Users
Here are some interesting excerpts from the white paper.

“Application based interoperability testing is certainly required and effective for testing the typical usage scenarios that are likely to be encountered. However, the PDF (or any other PDL) language specification is over 1000 pages and there are hundreds of different PDF operators and attributes can be included in a perfectly valid PDF file. Nearly all of PDF creators and applications that exist today output only a subset of the full PDF language specification. Therefore, no matter how many different files one may produce using various applications, the resulting PDF output files would not cover the full breadth of the PDF language specification. Conformance to the PDF language specification cannot be achieved by using just application produced PDF files leaving the PDF vendor with potentially significant risk and exposure.

“With so many PDF implementations out in the marketplace, leaving this type of exposure can result in a significant competitive disadvantage for your product – it is certain that new versions will make use of PDF functionality that have not been used before. PDF conformance testing is critical to producing robust PDF implementations.”

“Interoperability testing using application generated test files is important but not sufficient to provide an effective testing coverage for the target PDF printer or application. An effective testing strategy must include conformance testing against what the target PDL language allows.”

Testimonial from an actual user:

“The PDF FTS is a very efficient test tool for the purpose of verifying PDF conformance. This test suite covers full PDF specification and can be executed within a short time. It is also an efficient tool to qualify each product for “fundamental” test. The PDF FTS has helped to find out unknown anomalies in early stage, which cannot be found by using the PDF files produced by applications alone.”

Any questions or comments about this white paper are welcomed.