Background picture determination method e.g. for traffic surveillance, involves determining background picture and from time T1 free areas of picture are determined

摘要

The method involves determining a background picture and from time T1 free areas of a picture are determined. For the free areas the background picture (H1) is provided, with a first mask. At time T1, the covered areas are masked and a second mask is provided at a second time. By comparison of the masks, free areas are determined, and the background picture is extended by the background of the freed areas. An independent claim is included for a device.