
A basic bidimensional scalar field [Un champ scalaire bidimensionnel basique].
                    (y=511)   ff ff ... ff ff
                    (y=510)   ff ff ... ff ff
                    (y=509)   fe fe ... fe fe
                    (y=508)   fe fe ... fe fe
                    (y=507)   fd fd ... fd fd
                    (y=506)   fd fd ... fd fd
                      ...     .. .. ... .. ..
                      ...     .. .. ... .. ..
                      ...     .. .. ... .. ..
                    (y=005)   02 02 ... 02 02
                    (y=004)   02 02 ... 02 02
                    (y=003)   01 01 ... 01 01
                    (y=002)   01 01 ... 01 01
                    (y=001)   00 00 ... 00 00
                    (y=000)   00 00 ... 00 00
(x=000 ......... 511)each point being coded using one byte (given as an hexadecimal value).
