kovidgoyal, thanks for html2lrf, it works great!
Just noticed some problems, small inline images tend to get scaled up and many images that aren't very high tend to throw new pages before and after when they aren't needed. I always find this Gutenberg document a great one for testing image formatting
http://www.gutenberg.org/files/19499/19499-h.zip
Noticed the "--font-delta" option only tends to work for headers not text paragraphs. Is it possible to add an option to format images to a specified number of colours? - I always find pictures with 16 colours work well on the reader and saves lots of space.