Originally Posted by megahunter
I've got an idea for a plugin which I think would be very useful to everyone.
When a book doesn't have a cover in the online databases (random current books, old books, freely available books...), we have the possibility to generate one based on the metadata. Would it not be possible to write a plugin that would give you the ability to extract the first page of the book file and convert it as an image to be used as the cover in one click?
I know one commercial ebook library software does it from PDFs (though I can't remember which) and it was one of the few assets that made me hesitate between Calibre and that software.
Did you realise you can do this already in Calibre? From the individual Edit Metadata screen for a book, on the right side of "Available Formats" you can click on the icon up the top left to pull an image out of a book format (if the book has one). You can also do the same thing from the bulk metadata dialog, if you look at the bottom where it says "Change cover" and choose "Set from ebook file(s)".
Your other option if the book has none is to generate a cover using the book metadata (title/author/series). Calibre has a very basic version of that ability built in (look for "Generate default cover". There is also an enhanced customisable alternative available as a plugin on this forum called "Generate Cover".