procedure TForm1.aaa(bmpFrom, bmpTo: Tbitmap);
var
  TmpImage, Monobmp: TBitmap;
  IRect: TRect;
begin
  MonoBmp := TBitmap.Create;
  TmpImage:=Tbitmap.Create;
  TmpImage.Width := bmpFrom.Width;
  TmpImage.Height := bmpFrom.Height;
  IRect := Rect(0, 0, bmpFrom.Width, bmpFrom.Height);
  TmpImage.Canvas.Brush.Color := clBtnFace;
  try
    with MonoBmp do
    begin
      Assign(bmpFrom);
      Canvas.Brush.Color := clBlack;
      if Monochrome then
      begin
        Canvas.Font.Color := clWhite;
        Monochrome := False;
        Canvas.Brush.Color := clWhite;
      end;
      Monochrome := True;
    end;
    with TmpImage.Canvas do
    begin
      Brush.Color := clBtnFace;
      FillRect(IRect);
      Brush.Color := clBlack;
      Font.Color := clWhite;
      CopyMode := MergePaint;
      Draw(IRect.Left + 1, IRect.Top + 1, MonoBmp);
      CopyMode := SrcAnd;
      Draw(IRect.Left, IRect.Top, MonoBmp);
      Brush.Color := clBtnShadow;
      Font.Color := clBlack;
      CopyMode := SrcPaint;
      Draw(IRect.Left, IRect.Top, MonoBmp);
      CopyMode := SrcCopy;
      bmpTo.assign(TmpImage);
      TmpImage.free;
    end;
  finally
    MonoBmp.Free;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  aaa(image1.picture.bitmap, image2.picture.bitmap);
  Image2.invalidate;
end;