Add PDF support

[quinn]

Hi, I was considering how to create image thumbnails for my pdf uploads using carrierwave. It seems there is a plan to support this within this project.. I know it isn't implemented yet, but have you thought at all how it would work? Let me know and I'd be happy to try and implement it.

[amiel]

Hi @quinn, I haven't thought specifically on how creating pdf thumbnails would work. I imagine I would start by tinkering with imagemagick to see what works.

I won't be able to work on this in the near future, so go for it. Take a look at lib/thumbkit/processor/text.rb for an example, I think it should get you pretty close. In fact, you may be able to use Thumbkit::Processor::Text to thumbnail pdfs. Just try mapping the .pdf extension by adding

  'pdf' => 'Text',

to lib/thumbkit/processor.rb.

Good luck, and let me know what you come up with.