GrayScaleToDuotone example for Delphi
procedure TForm1.GrayScaleToDuotone1Click(Sender: TObject);
begin
{ Change the bitmap to grayscale bitmap }
LEADImage1.GrayScale( 8 );
{ Apply duotone conversion }
LEADImage1.GrayScaleToDuotone( Nil, RGB(255, 0, 0), DT_REPLACE );
end;