function bmp2emf(const SourceFileName: TFileName): Boolean;
// Converts a Bitmap to a Enhanced Metafile (*.emf)
var
 Metafile: TMetafile;
 MetaCanvas: TMetafileCanvas;
 Bitmap: TBitmap;
begin
 Metafile := TMetaFile.Create;
 try
 Bitmap := TBitmap.Create;
 try
 Bitmap.LoadFromFile(SourceFileName);
 Metafile.Height := Bitmap.Height;
 Metafile.Width := Bitmap.Width;
 MetaCanvas := TMetafileCanvas.Create(Metafile, 0);
 try
 MetaCanvas.Draw(0, 0, Bitmap);
 finally
 MetaCanvas.Free;
 end;
 finally
 Bitmap.Free;
 end;
 Metafile.SaveToFile(ChangeFileExt(SourceFileName, '.emf'));
 finally
 Metafile.Free;
 end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
 bmp2emf('C:\TestBitmap.bmp');
end;