摘要 |
Four pictures may be taken from a fixed standpoint at given regularly-spaced times (t1-t4). Movement of several individual vehicles (1-3) may be followed. Pairs of pictures are subtracted (Subtraktion), to give a set of difference pictures (B1,B2). Various reflecting surfaces on the moving vehicles (12star,12starstar) may show up on the difference pictures. Further processing may show up differences of vehicle positions as white areas on a black background on modified difference pictures (B1star,B2star). |