12 typedef unsigned char GrayLevel;
13 typedef std::vector<GrayLevel> Container;
28 void fill( GrayLevel g );
40 GrayLevel
at(
int i,
int j )
const;
46 GrayLevel&
at(
int i,
int j );
55 std::pair<int,int> position(
Iterator it )
const;
57 bool importPGM( std::istream & input );
58 bool exportPGM( std::ostream & output,
bool ascii =
true );
64 int index(
int x,
int y )
const;