Nathan Willis (Linux.com) compares three Linux-based utilities for generating photo mosaics – Pixelize, Metapixel, and Imosaic. It is hard to pick a best program from among the three apps – he concludes. Metapixel offers many mosaic creation options, but it lacks a graphical interface.
Photo mosaics are recreations of one large image composed of tiny tiles of other smaller images. They can be a fun project and make good use of the hundreds of less-than-extraordinary photos on your hard drive.