procedure TForm1.Button1Click(Sender: TObject);
var
 x, y: integer;
 i, j: integer;
 r, g, b: integer;
begin
 Form1.Canvas.Pen.Width := 10;
 Form1.Canvas.MoveTo(10, 10);
 Form1.Canvas.LineTo(90, 20);
 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;