Collective.pdfpeek is a project mainly written in PYTHON and JAVASCRIPT, it's free.
Generate image previews of PDF files uploaded to Plone
PdfPeek is a Plone 4 add-on product that utilizes GNU Ghostscript to generate image thumbnail previews of PDF files uploaded to ATFile based content objects.
This product, when installed in a Plone 4.x site, will automatically generate preview and thumbnail images of each page of uploaded PDF files and store them annotated onto the content object containing the PDF file.
Image generation from the PDF file is processed asynchronously so that the user does not have to wait for the images to be created in order to continue using the site, as the processing of large PDF files can take many minutes to complete.
When a file object is initialized or edited, PdfPeek checks to see if a PDF file was uploaded. If so, a ghostscript image conversion job is added to the pdfpeek job queue. If the file uploaded is not of content type 'application/pdf', an image removal job is added to the pdfpeek job queue. This job queue is processed periodically by a cron job or a zope clock server process. The image conversion jobs add the IPDF interface to the content object and store the resulting image preview and thumbnail for each page of the PDF annotated on to the content object itself. The image removal jobs remove the image annotations and the IPDF interface from the content object.
If a job fails, it is removed from the processing queue and appended to a list of failed jobs. If a job succeeds, it is removed from the processing queue and appended to a list of successfully completed jobs.
PdfPeek ships with an example user interface that is turned on by default. This UI displays the thumbnail images of each page of the PDF file when a user views the content object in their browser. This example UI is not quite working yet, and is meant to be just that, an example. I don't claim to be a javascript master.
A custom traverser is available to make it easy to access the images and previews directly, as well as to build custom views incorporating image previews of file content.
PdfPeek ships with a configlet that allows the site administrator to adjust the size of the generated preview and thumbnail images, as well as toggle the example user interface and default event handlers on and off.
Requires the GNU ghostscript gs binary to be available on the $PATH!
Tested on POSIX compliant systems such as LINUX and MacOS 10.6. Untested on Windows systems. (Wouldn't be surprised if it works, as long as you can install gs.)
As of version 0.17, Plone 3.x is no longer officially supported.