Automatic reading of analog display instruments

A general design strategy based on experiences of a successful application project concerning the reading of analog devices in order to automate the reading process is presented. The problem space is defined and a description language is introduced which controls the interpretation of specific types of instruments and decouples recognition of primitiva and formation of an aspired result. Furthermore, the interaction between Hough transform or line detection, the user-controlled computation of the measurement and the extension to other measuring instruments is described.