Provided are a multi-phase transformer having an easier-producible structure, and a transformation system wherein a plurality of such transformers are serially connected. The method comprises the steps of selecting a first portion of pictures from a stream of pictures fulfilling a quality measure for processing in a first processing unit PROC1, and selecting a second portion of pictures not fulfilling said quality measure for processing in a second processing unit PROC2. The second end portion of the one-dimensional nanostructure functions as a polarized electron emission tip and is configured for emitting a spin-polarized electron currentbeam under an effect of selectably one of a magnetic field induction and a circularly polarized light beam excitation when a predetermined negative bias voltage is applied to the cathode. The camera identifies an obstruction when any portion of the indicium is obscured.