Качественно уменьшить изображение

procedure TForm1.Button1Click(Sender: TObject);
begin
  Form1.Canvas.Font.Size := 24;
  Form1.Canvas.TextOut(0, 0, 'Text');
  Form1.Canvas.CopyRect(Bounds(0, 50, 25, 10), Form1.Canvas,
  Bounds(0, 0, 100, 40));
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  x, y: integer;
  i, j: integer;
  r, g, b: integer;
begin
  Form1.Canvas.Font.Size := 24;
  Form1.Canvas.TextOut(0, 0, 'Text');
  for y := 0 to 10 do
  begin
    for x := 0 to 25 do
    begin
      r := 0;
      for i := 0 to 3 do
        for j := 0 to 3 do
          r := r + GetRValue(Form1.Canvas.Pixels[4*x+i, 4*y+j]);
      r := round(r / 16);
      g := 0;
      for i := 0 to 3 do
        for j := 0 to 3 do
          g := g + GetGValue(Form1.Canvas.Pixels[4*x+i, 4*y+j]);
      g := round(g / 16);
      b := 0;
      for i := 0 to 3 do
        for j := 0 to 3 do
          b := b + GetBValue(Form1.Canvas.Pixels[4*x+i, 4*y+j]);
      b := round(b / 16);
      Form1.Canvas.Pixels[x,y+50] := RGB(r, g, b)
    end;
    Application.ProcessMessages;
  end;
end;