In order to safeguard a hazardous area, in particular the hazardous area
of an automatically operating machine, images of the hazardous area are
recorded with at least a first and a second image recording unit that are
arranged offset from one another. The images of the scene are subjected
to three-dimensional scene analyses using different three-dimensional
scene analysis methods, and the hazardous area is safeguarded when at
least one of the scene analysis methods detects a foreign object.