What is the purpose of the black and white stickers on test aircraft? I want to ask what is the purpose of black and white stickers used on test aircraft. 

The following is a picture:



I have seen variations of such stickers. Does anyone know what is reason for their use ?
They look very much like position markers to identify known points on the aircraft, for analysing video footage.  You see similar markers on crash-test dummies used in vehicle impact trials, for instance, and also in motion-capture in the synthetic movie industry (and in orthopaedics).