INTERFACE FunSlopeFeatures2D;
(*
  A feature mapper that returns the function and the gradient modulus,
  computed from the pixel and its 4 nearest neighbors. 
  Each image layer generates 2 consecutive features. *)

IMPORT FeatureMapper2D AS Mapper;
FROM Mapper IMPORT NAT;

TYPE
  T <: Public;
  Public = Mapper.T OBJECT METHODS
      init(NL: NAT): T; (* Initializes the mapper for "NL" layers. *)
    END;

END FunSlopeFeatures2D.