Letterboxing's the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio. The resulting videographic image has mattes (black bars) above and below it; these mattes are part of the image (for example, of each frame of the video signal). LTBX's the identifying abbreviation for films and images so formatted. The term refers to the shape of a letter box, a slot in a wall or door through which mail's delivere… (More on Letterboxed)