An apparatus comprising a detector for detecting optical density levels
recorded on a film, each optical density level representing a symbol from
a constellation of symbols, wherein each symbol is associated with a
plurality of bits of data; and a demapper, for receiving data responsive
to the detected optical density levels, and for providing data associated
therewith. A method for recovering data stored on film by detecting
optical density levels recorded on the film; and recovering the data from
the detected optical density levels by receiving data responsive to the
detected optical density levels; and demapping said received data for
providing the recovered data associated therewith; wherein each detected
optical density level is associated with a symbol from a constellation of
symbols for use in demapping the data, and wherein each symbol is
associated with a plurality of bits of data.