Method and system for monitoring a spatial area in a personnel interlock

A monitoring system for monitoring a spatial area in a personnel interlock and for monitoring of separation of persons, wherein the system is programmed, with respect to the personnel interlock, a method that comprises:

• receiving image data which represent a plurality of depth images of the spatial area which have been acquired simultaneously and from different positions in an area of the personnel interlock, in each case by a respective 3D image sensor arranged at the different positions, wherein each of the depth images indicates, for each of its pixels, a spatial distance of an object or portion thereof imaged thereon from the associated 3D image sensor on a asis of a pixel value assigned thereto;
• calculating, for each of the depth images, a characteristic depth image value associated with the respective depth image, on a basis of all of the individual pixel values or on a basis of a subset of the individual pixel values of the respective depth image;
• calculating a total image value by combining the characteristic depth image values of the various depth images in accordance with a predetermined monotonic combination rule;
• and
• determining an estimation result for a probability that more than one person is present in the spatial area, in dependence upon a result of a comparison of the total image value with at least one predetermined reference total image value.