1. A method of obtaining feedback information, which relates to fabrication of patterns on a wafer based upon fabrication data, the fabrication data derived from design data, comprising: capturing for at least one inspection region at least one image of patterns within the inspection region using an imaging device; automatically generating from data selected from the fabrication data and the design data, a reference pattern for the inspection regions, a reference pattern comprising a machine-readable representation of at least one of (a) one or more line segments and (b) one or more curves; detecting edges within each of the images; determining, from the detected edges, one or more measurements for each of the selected patterns; and processing the measurements to form statistical information and obtain the feedback information.