| 摘要 |
PURPOSE: To detect a plurality of vehicles separately even when images of the vehicles are taken partly in an overlapping state by a monitor camera. CONSTITUTION: A characteristic extraction circuit 4 takes a difference between a present image photographed by a monitor camera 1 and a background image within a background-preserving memory 10, and stores the difference in an image memory 5-1. A CPU2 extracts line data of a part corresponding to the difference in the image memory 5-1 by using an image memory 5-2, and then stores values of XY coordinates of the line data with using time as a parameter in an internal memory 12. The process is carried out for a certain time. After the values of XY coordinates with time as the parameter are accumulated in the internal memory 12, an operation circuit 6 draws a figure of the line data with the lapse of time in three-dimensional space, i.e., in space having X axis, Y axis and time axis from the values of XY coordinates with time as the parameter. The CPU2 detects based on the figure whether line data appearing at a different time become the same line data afterwards. Accordingly, passing of a plurality of vehicles is separately detected even if the vehicles partly overlap each other. |
