alphagov/whitehall — pull request #1645 by tekin (2014-08-05 13:55:07+00:00)
Title: Use Ghostscript to generate PDF thumbnails

ImageMagick cannot convert PDF to images by itself and instead delegates
to Ghostscript. By bypassing ImageMagick and going to Ghostscript
directly, we see a big improvement in thumbnail generation speed:

Test file 1 with ImageMagick: 30.7 seconds
with Ghostscript: 1.5 seconds
Test file 2 with ImageMagick: 30.7 seconds
with Ghostscript: 1.2 seconds
Test file 3 with ImageMagick: 31.4 seconds
with Ghostscript: 1.7 seconds

Story: https://www.agileplannerapp.com/boards/173808/cards/5258