From the webpage:
The BioID Face Database has been recorded and is published to give all researchers working in the area of face detection the possibility to compare the quality of their face detection algorithms with others. It may be used for such purposes without further permission. During the recording special emphasis has been placed on “real world” conditions. Therefore the testset features a large variety of illumination, background, and face size. Some typical sample images are shown below. (click to enlarge the images)
Just in case you are interested in face detection + topic maps.
I first saw this in Face detection using Python and OpenCV.