Suggestions on generating abstract little images like StackOverflow 'flair' image

Question

Hi All, I'm creating a webapp that has various unrelated data types (House, Contact, Article, Recipe, Fact -etc). I am giving each one a 'thumbnail' automaticaly. (User can then manually upload there own image).

Currently, I'm grabbing an image from Flikr, crop or strech to 80x80 & adding a mosaic filter at 10 pixels. The result is a nice little abstract thumbnail for each peice of data. (This lets me user 'CoverFlows, Carusel etc - for a more visual experience).

I'd now like to collect some other suggestions on 'image generation'.

I'd love to know how StackOverflow creates those nice little patterns for each user. (Geometric pattern generator? Any open Api?) [So much nicer than the old grey silouette!

All suggestions welcomed! Thanks

Answer 1

That's actually not Stack Overflow but Gravatar creating those images. They are Identicons created from a hash of the user's email address. The linked Wikipedia article also lists several implementations.

There are also some Stack Overflow questions on that topic:

• What is the algorithm used to generate those little Gravatar identicon images?
• How Do I Generate Random Identicons?