I have two friends that want to create a jewelry store, focused on customized jewels. The core feature is the jewelry designer, based on a jewel model.
Here's an example of the sort of thing I am looking to create : http://www.gemvara.com/jewelry/wisteria-pendant/pear-citrine-18k-yellow-gold-pendant-with-diamond/155hhg
You can use the menu on the right to change different areas of the final image, such as the gems or metal used. If you right-click on the image, you can see it's a complete jpg.
How is this kind of dynamic image designed and programmed in the back-end?
UPDATE
I worked with ImageMagick a long time ago, and it's seems it could be used. My guess is: Gemvara has a large number of raw images (like gems colors, jewels models, etc), and the back-end service (the image generator) uses some lib like ImageMagick to combine those images and generate in different number of perspectives (like the coin comparison).
I want to know if someone has other ideas of how I can combine different images or maybe even generate the different gems colors programmatically. Because the images combinations seems the best way to generate such good images, but to take/create those images is a HUGE job.