DATA PROCESSING APPARATUS

摘要

A method of operating a data processing apparatus is provided. The method includes receiving video data; receiving a virtual test signal representative of a location of a virtual object; setting data representing the horizontal and vertical size of the virtual object dependent upon the location of the virtual object; overlaying the received video data with an image of the virtual object at locations determined from the virtual test signal to generate virtual test video data; and analysing the virtual test video data and generating an alarm signal based on an output signal generated by said analysis.