A method of evaluating a movement event within an area, which movement event is detected using an image sensor emitting image data, characterised in that a trajectory of an object describing a movement and a property of the moved object within the area is identified from the image data, which trajectory comprises coordinate values as well as the size and colour of the object as property values and time values, wherein the trajectory is matched with a first reference trajectory verified as a usual event and with a second reference trajectory verified as an alert event, which reference trajectories are stored in a database, under determination of a similarity measure, which reference trajectories comprise reference coordinate values and reference time values as well as the size and colour of a reference object as reference property values and reference time values, wherein a trajectory function describing the time course of at least one coordinate value as well as the size and colour of the object as a property value of the trajectory and a reference function describing the time course of at least one reference coordinate value as well as the size and colour of the reference object as reference property values of each of the reference trajectories and/or at least one trajectory parameter of the trajectory, identified from the trajectory function or from the trajectory by applying the teaching of curve sketching, which trajectory parameter comprises a relative time specification and an area specification, and one reference parameter of the reference trajectories, determinable from the respective reference function or the respective reference trajectory by applying the teaching of curve sketching, which reference parameter comprises a relative reference time specification and a reference area specification, are compared to determine the similarity measure. which movement event is detected using an image sensor emitting image data, characterised in that a trajectory of an object describing a movement and a property of the moved object within the area is identified from the image data, which trajectory comprises coordinate values as well as the size and colour of the object as property values and time values, wherein the trajectory is matched with a first reference trajectory verified as a usual event and with a second reference trajectory verified as an alert event, which reference trajectories are stored in a database, under determination of a similarity measure, which reference trajectories comprise reference coordinate values and reference time values as well as the size and colour of a reference object as reference property values and reference time values, wherein a trajectory function describing the time course of at least one coordinate value as well as the size and colour of the object as a property value of the trajectory and a reference function describing the time course of at least one reference coordinate value as well as the size and colour of the reference object as reference property values of each of the reference trajectories and/or at least one trajectory parameter of the trajectory, identified from the trajectory function or from the trajectory by applying the teaching of curve sketching, which trajectory parameter comprises a relative time specification and an area specification, and one reference parameter of the reference trajectories, determinable from the respective reference function or the respective reference trajectory by applying the teaching of curve sketching, which reference parameter comprises a relative reference time specification and a reference area specification, are compared to determine the similarity measure. <EOS>