1. A method for automatically determining a best non-integer granularity in a machine vision system, the method comprising: using a processor running a program to generate a plurality of integer values of granularity; using the processor to compute a quality rating for each integer value of granularity; using the processor to determine a best integer value of granularity by determining the integer value of granularity having the greatest quality rating; and using the processor to interpolate a best non-integer value of granularity using the best integer value of granularity, and nearest neighbor integer values of granularity.