View source for 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.

<u>Now the 100000 $US question:</u> ''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 [http://bugs.kde.org/attachment.cgi?id=19542&action=view #19542] and [http://bugs.kde.org/attachment.cgi?id=19543&action=view #19543] (from KDE [http://bugs.kde.org/show_bug.cgi?id=140006 #140006]).