Paint Bitmap Canvas

var
  Starter : Boolean;
  
//

procedure TForm1.FormPaint(Sender: TObject);
var
  X, Y, W, H: LongInt;
begin
  if not Starter then exit;
  with image1.picture.bitmap do begin
  W := Width;
  H := Height;
  end;
  Y := 0;
  while Y < Height do begin
  X := 0;
    while X < Width do begin
    Canvas.Draw(X, Y, image1.picture.bitmap);
    Inc(X, W);
  end;
  Inc(Y, H);
end;
end;

Beispiel :

procedure TForm1.Button1Click(Sender: TObject);
begin
  Starter:=true;
  paint;
end;