In one embodiment, a system includes a fuel nozzle that includes a fuel injector that includes a fuel port and a premixer tube. The image processing method may reduce the power consumption by classifying an input content into a conversion target region and a preservation target region and by converting a luminance of pixels included in the conversion target region. Exemplary embodiments of the door safety system may further include a housing that comprises: a fastening mechanism; an alarm system; a means for mounting the housing to a wall; a front body; and a mounting body.