An image enhancing system uses a perfect reconstructing filter to process image signals within a specified resolution and enhance the image signals. The active waveguide has an input port for receiving an optical signal to be amplified and an output port on which an amplified optical signal is directed. The tag is adapted to respond to an interrogatory signal by wirelessly transmitting a signal comprising the metadata, e. The ventilation interface has differing gas line entry ports and can be shallow with a relatively deep soft facial interface or deep with a relatively shallow facial interface.