Methods and systems are provided for defining, identifying and learning geometric features. The system includes a first light source configured to emit light onto a first side of the film in a first predetermined region of the film. The two sets of image data can be collected in many different ways and may include using a retroreflector as the reflector. An input signal is applied to the encoder where the signal is provided to an M channel encoder circuit including a filter bank having a total bandwidth partitioned among M adjacent or overlapping filters. The method also includes delineating a stab depth measurement on the outer surface of the pipe, inserting the pipe into the passage until the stab depth measurement is adjacent the faced end, and forming a socket fusion joint having a uniform fusion length FL=d1.