A GIMP Python plugin to create PNG thumbnails out of PDF files' first page, for book covers.
It crawls recursively a folder path looking for PDF files. Out of each PDF file, it will create a PNG thumbnail of the first page in the PDF.
This plug-in must be put in The GIMP's script directory (e.g., $HOME/.gimp-1.2/plugins) and made executable (e.g., chmod +x).
For interactive invocation, run The GIMP and go to Tools -> PDF Cover Thumbnail...
New width and height are in pixels.