Convert pdf to ithmb Online: pdf2ithmb
You can use Tom's Editor to easily convert images from
Portable Document Format .PDF to iPod Thumbnail
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Adobe PDF format is the most popular document format. Overcomplicated. Offers compression.
ITHMB are thumbnails used by various Apple devices. At first these images were used by iPhods but now can be found on iPhones and iPads.