Embodiments disclosed herein provide methods, apparatus and computer systems comprising an input unit for inputting one or more data sets to be processed comprising a capacitance measuring device configured to measure one or more conductive elements on a sensor plane and provide a corresponding data set of measurements obtained from the conductive elements. A computing unit is coupled to the input unit and for processing the data sets； the computing unit comprises at least one processor with non-transient memory. An output unit is connected to the computing unit for outputting data received from the computing unit. A computer program stored in memory comprising instructions that cause the computer to isolate and discharge conductive and reference impedance elements, perform a charge transfer to the one or more conductive elements on the sensor plane, measure the relative difference between the conductive elements and reference impedance element, and store measurements in non-transient memory.
