procedure TForm185.Button1Click(Sender: TObject);
const
 FieldSize = 32;
 FrameSize = 3;
var
  LBitmap: TBitmap;
  LDest: TBitmap;
begin
  LBitmap := TBitmap.Create;
  try
    LBitmap.LoadFromFile('square.png');

    LDest := TBitmap.Create;
    try
      LDest.SetSize(LBitmap.Width + FieldSize * 2, LBitmap.Height + FieldSize * 2);

      LDest.Canvas.BeginScene;
      try
        LDest.CopyFromBitmap(LBitmap, TRect.Create(0, 0, Round(LBitmap.Width), Round(LBitmap.Height)), FieldSize, FieldSize);

        LDest.Canvas.Stroke.Color := TAlphaColorRec.Limegreen;
        LDest.Canvas.Stroke.Thickness := FrameSize;
        LDest.Canvas.DrawRectSides(TRectF.Create(0, 0, LDest.Width, LDest.Height), 0, 0, AllCorners, 100, AllSides, TCornerType.Bevel);
      finally
        LDest.Canvas.EndScene;
      end;

      LDest.SaveToFile('square_new.png');
    finally
      LDest.Free;
    end;
  finally
    LBitmap.Free;
  end;
end;