Bitmap Mirror H/V

procedure MirrorV(AImage: TImage);
var
  lBmp: TBitmap;
begin
  lBmp := TBitmap.Create;
  try
    lBmp.Assign(AImage.Picture.Graphic);

    StretchBlt(lBmp.Canvas.Handle,
                 0,
                 0,
                 lBmp.Width,
                 lBmp.Height,
               lBmp.Canvas.Handle,
                 0,
                 lBmp.Height,
                 lBmp.Width,
                 -lBmp.Height,
               SRCCOPY);

    AImage.Picture.Assign(lBmp);;
  finally
    lBmp.Free;
  end;
end;

procedure MirrorH(AImage: TImage);
var
  lBmp: TBitmap;
begin
  lBmp := TBitmap.Create;
  try
    lBmp.Assign(AImage.Picture.Graphic);

    StretchBlt(lBmp.Canvas.Handle,
                 0,
                 0,
                 lBmp.Width,
                 lBmp.Height,
               lBmp.Canvas.Handle,
                 lBmp.Width,
                 0,
                -lBmp.Width,
                 lBmp.Height,
               SRCCOPY);
               
    AImage.Picture.Assign(lBmp);;
  finally
    lBmp.Free;
  end;
end;

Beispiel :

procedure TForm1.Button1Click(Sender: TObject);
begin
  MirrorH(Image1);
  Mirrorv(Image1);
end;