A method and apparatus for quantising data in a data compression system involves receiving original data in the form of a plurality of discrete data values. Cosmetic, dermocosmetic, dermopharmaceutical or pharmaceutical composition including it. The depth gage is coupled to the body and is movable relative thereto generally perpendicular to the shaft of the bone. The control circuitry varies the pull-down control signal to decrease a selected one of the tip and ring line currents in response to a sensed current corresponding to an associated one of a tip pull-down current and a ring pull-down current. The user interface includes a number of fields through which the user can view media content and modify the media representation being generated.