| The CMU Pose, Illumination, and Expression (PIE) Database Recent countries visiting this post |  |
 | 50 | United States |
 | 12 | |
 | 4 | Taiwan |
 | 3 | United Kingdom |
 | 2 | Italy |
 | 2 | India |
 | 2 | Russian Federation |
 | 1 | Germany |
 | 1 | China |
 | 1 | Turkey |
 | 1 | France |
 | 1 | Singapore |
 | 1 | Israel |
 | 1 | Japan |
 | 1 | Sweden |