Printing/Compare PDFs
Sometimes you are in need of quickly comparing 2 PDFs (which seem to represent the same page images) for any obvious or non-obvious differences. For instance because you have been printing the same source document to the "Print to File (PDF)" printer in KDEPrint.
Here is how to achieve this very fast:
- load the 2 files into kpdf
- make both kpdf windows use same size
- make one kpdf window exactly overlay the other
- make both kpdf windos use the same scaling
- make both kpdf windows show the same page viewport
(best is to use "maximize window", and scale to "Fit Width" or "Fit Page"). Next:
- identify both "minimized window" buttons in the taskbar
- the buttons should be next to each other
- move the mouse wheel to the taskbar
- scroll mousewheel up & down to quickly toggle windows
The fast switching between the two KPDF windows will help you easily identify any differences (even very small ones) between the two similar PDF pages.
A similar effect can be obtained by loading the PDFs into two Konqueror tabs (which embed kpdf) and using the mouse wheel to quickly toggle between the two tabs.
Now the 100000 $US question: What would you do to identify similar differences in *PostScript* (instead of PDF) files?
(You can use this trick for example to find the differences between the two PDFs from KDE bugzilla attachments #19542 and #19543 (from KDE #140006).