Apparatus and computer program for generating a feedback code

An apparatus for sampling data corresponding to a property of an object and generating a feedback code indicating the quality of the sampled data, said apparatus comprising

• (a) an input probe for generating-digital data points at a plurality of sample points on the surface of the object, each digital data point comprising a property value and a position value corresponding to a particular sample point;
• (b) an output device arranged to provide the feedback code;
• and
• (c) a processor electrically connected to said input probe and said output device and arranged to analyze the digital data and provide a feedback code indicating the quality of the digital data points, wherein said processor is programmed to
• (i) assign each digital data point to one of a plurality of discrete compartments based on the position value of the data point, each compartment corresponding to a unique location on the object and comprising zero, one, or more digital data points;
• (ii) determine a quality value for each of said compartments based on the quality of the digital data points assigned to that compartment and assign to each compartment a feedback code representing said quality value;
• and
• (iii) transmit said feedback code to the output device.