We're working on an algorithm for processing images of cells, similar to but much more basic than Cell Profiler, and we are looking for a large database of cell images to test our software. Can anyone point us in the right direction? We found the Cell Image Library immediately, but it seems almost empty.
There is a yearly contest on cell tracking organized by the IEEE International Symposium on Biomedical Imaging, and the associated data sets are freely available.
See for example: http://www.celltrackingchallenge.net/
I've actually answered my own question. The creators of Cell Profiler mentioned a database of biological images which they used to benchmark their software, and it appears to be available at http://www.broadinstitute.org/bbbc/