Monday, June 11, 2007

PDF Compare

Problem: I want to compare the output, in PDF format, of reports generated by one build of the software with the reports generated by "the current" build.

In other word, I need to compare the system under test to the golden results oracle.

I've posed this problem to many people over the years and have never gotten a satisfactory answer. Today, working from home, I am doing my own investigation into the solution.

Problem Refined: After some investigation I discovered that the document comparison tools were designed for the legal industry (my opinion, not a fact) and are not intended to be "image" checkers. As a result, I am now looking for a tool to tell me the "text" differences between PDF documents. Programs for picture/icon/color/placement differences will have to be left to the GUI test automation tools.

Diff DocDiff Doc site This Diff Doc tool looks like something worth test driving. The webpage says it will do exactly what I need.

The Diff Doc website had testimonials that rang true. The product documentation is available online and I was able to read about the PDF features.

Test drive of the easily installed trail software was straight forward. Detected 2 values that have changed in the ANA method file (XML). With the sheet music test I learned that the images are stripped and only the text is compared. Diff Doc found the differences in the chords and the change of title and comment lines. This may just do for me at work, assuming that the text and data values are important and the layout and icons are verified via another method.

Law Firms need such a tool Law firms like yours use advanced utilities to increase productivity (proof-reading at $100 per hour or more can be pretty expensive) and eliminate errors. The leading comparison tools in the legal market today are CompareRite from Lexis (no longer support CompareRite) and DeltaView from Workshare Technologies. These tools offer easy to use and powerful comparison features that make changing documents an easy and error-proof task. The products may be used stand-alone or integrated with a document management system.

None of the testimonials on the Workshare DeltaView site were compelling to me, I don't care that their partner thinks they rock. I don't have a global organization with lawyers who don't know how to use computers. The way they don't mention price leads me to believe that their sales organization and senior management get paid to much. I am not going to bother with their "free" download. Besides, they don't mention PDF in their so called technical page.

Other Uses Beyond Compare In addition to file comparison for test results this would also be a replacement for Beyond Compare? Beyond Compare is good for folder but it does not handle PDF (as far as I can tell.)

These are the files I used to evaluate the trial software installs. BPX 2\APF_ANA Screen with MDSS_101001_SW2_v2.xml BPX 1.x\APF_ANA Screen_101001_SW1_v2.xml

Blackthorn_Stick.pdf Blackthorn_Stick-7024.pdf


Litéra said...

Thanks dude, very nice article on Pdf Comparison

ptrusk said...

If you use, or can use, a Mac, check out PDF Comparator which uses Mac OS X's built in ability to render PDFs to create two images, and then compares them pixel by pixel, and displays the differences in color:

Erkki Solvak said...

Pdf Comparer works on the Mac and Windows: