Method for determining the length of a queue

摘要

Method for determining the length of a queue of objects in a predefined region having at least one entrance and at least one exit, in the course of which errors in the acquisition of objects entering or exiting the region are corrected during the determination of the length of the queue. In a first step, a specific entry signature E of each object entering the predefined region through the at least one entrance is determined with the aid of at least one first image sensor. Thereafter, the specific entry signature E is stored in an entry list of a calculation unit, each entry signature E being provided with an index value i reflecting the temporal sequence of the entries. In addition, a value L reflecting the length of the queue of the objects is increased by one. Furthermore, a specific exit signature A of an object exiting the predefined region through the at least one exit is determined with the aid of at least one second image sensor, the specific exit signature A being stored in an exit list of a calculation unit as exit signature A0 with index value j=0. The index value of exit signatures Aj already present in the exit list is respectively increased by one, and exit signatures Aj which have an index value j that is greater than a predeterminable value M are deleted from the exit list. Subsequently, similarity values Cn for −N≦n≦+N are calculated with the aid of the calculation unit, N being a predeterminable value which defines a specific number N of entry signatures of objects which, before or after the object with the entry signature EL which next exits the predefined region on the basis of the length of the queue L, will exit or have already exited the predefined region. In the process, similarity metrics Umn are respectively calculated between an exit signature Am and an entry signature EL+m+n, M running from 0 to M, and added to Cn. The value L is decremented by the value one. Subsequently, the similarity values Cn are compared with the similarity value C0. The value L is corrected by adding the index value x given the presence of a value Cx with index value n=x that indicates a higher similarity than the similarity value C0.

主权项

1. Method for determining the length of a queue of objects in a predefined region having at least one entrance and at least one exit, comprising the steps of:
a) determining with the aid of at least one first image sensor a specific entry signature E of each object entering the predefined region through the at least one entrance; b) storing the specific entry signature E in an entry list of a calculation unit, each entry signature E being provided with an index value i reflecting the temporal sequence of the entries, and a value L reflecting the length of the queue of the objects being increased by one; c) determining with the aid of at least one second image sensor a specific exit signature A of an object exiting the predefined region through the at least one exit; d) storing the specific exit signature A in an exit list of a calculation unit as exit signature A0 with index value j=0, the index value of exit signatures Aj already present in the exit list respectively being increased by one, and the exit signatures Aj which have an index value j that is greater than a predetermined value M being deleted from the exit list; e) calculating similarity values Cn for −N≦n≦+N with the aid of the calculation unit, N being a predetermined value which defines a specific number N of entry signatures of objects which, before or after the object with the entry signature EL whose exit is next expected on the basis of the length of the queue L, will exit or have already exited the predefined region, similarity metrics Umn respectively being calculated between an exit signature Am and an entry signature EL+m+n, m running from 0 to M, and added to Cn; f) decrementing the value L by the value one; g) correcting the value L by comparing the similarity values Cn with the similarity value C0, and correcting the value L by adding the index value x given the presence of a value Cx with index value n=x that indicates a higher similarity than the similarity value C0.