Computer implemented methods and computer program products have instructions for generating transfer functions that relate segments on lithography photomasks to features produced by photolithography and etching using such segments. Such methods may be characterized by the following elements: (a) receiving after development inspection metrology results produced from one or more first test substrates on which resist was applied and patterned using a set of design layout segments; (b) receiving after etch inspection metrology results produced from one or more second test substrates which were etched after resist was applied and patterned using said set of design layout segments; and (c) generating the transfer function using the set of design layout segments together with corresponding after development inspection metrology results and corresponding after etch inspection metrology results.