In image processing a spreading algorithm essentially transforms an image into another image by randomizing the rows and columns indexes. [0037] The following is an example of a spreading algorithm: FIN ??? ( NK , ??? KK , ??? k ) ??? := mod ??? [ KK ??? mod ??? ( k , ??? ceil ??? ( NK KK ) ) + floor ??? [ k ceil ??? ( NK KK ) ] ??? mod ??? ( KK ??? ceil ??? ( NK KK ) , ??? NK ) , ??? NK ] INX ???