A Visual Comparison Approach to Automated Regression Testing

A Visual Comparison Approach to Automated Regression Testing (PDF to PDF Compare)

• Type of software testing that seeks to uncover new bugs in existing functional areas of a system after changes have been made to them • Ensure that a change has not introduced new faults and that the intended results are still being produced Visual Regression Testing 2

Visual Regression Testing • 3

The Antenna House Problem • The need to regression test new releases of Antenna House Formatter • At least 8 maintenance releases a year • Has been done manually by visually comparing output of old and new files • • • Time consuming Prone to missing minor (but important) differences Can lead to delays in product releases Done only on candidate release versions Increase in support calls due to missed errors Visual Regression Testing • Regression Testing (Visual Method) 4

• Compare outputs visually, not the underlying code • High speed performance • Support for large collection of documents • Method to generate meaningful reports Visual Regression Testing Going Automated Challenges 5

Java application Automated visual comparison tool Precision pixel-by-pixel comparison of output documents Scalable & fast regression testing Regression testing of new releases of AH Formatter An automated system for comparing versions of rendering software or rendered output • Beyond regression testing • Pre-production system check • Stylesheet development • Installation validation • System(s) certification • • • Visual Regression Testing What is AHRTS? 6

How does it work? PDF 2 PDF 1 Extract PDF code as character strings Homogenize Properties Compare Is the content the same? Return XML Report Page No Difference PDF 2 Yes Homogenize Properties Visual Regression Testing Select PDF documents to be compared 7

How does it work? PDF 2 Compare Pixel by Pixel Page by Page Convert to Bitmap Return XML Report Page Difference No Are pages the same? Yes Convert to Bitmap No Create Composite Image of Differences Visual Regression Testing PDF 1 Return XML Report Page No Difference Format to PDF using XSL-FO 8

• Automates regression testing • High speed performance • 90%+ reduction in human effort • Handles large document comparisons • Significantly more accurate and reliable • Able to catch more subtle differences • Able to test more often, fewer problems results in overall better product • Fewer support issues Visual Regression Testing Benefits 9

Beyond regression testing, a PDF to PDF comparison tool like Antenna House Regression Testing System, can have a significant impact on improving software as it may play many roles in the development cycle for any system generating visual outputs. Visual Regression Testing Conclusion 10

Thank you! For more information: www. antennahouse. com celina@antennahouse. com