BitMiracle.LibTiff.Classic.Tiff.GetTagListCount C# (CSharp) Method

        public int GetTagListCount()
        {
            return m_dir.td_customValueCount;
        }

    public TiffGrid(string filename, string NewFileName)
    {
      ValuesToWrite = new Dictionary<int, Dictionary<int, double>>();

      tiff_org = BitMiracle.LibTiff.Classic.Tiff.Open(Path.GetFullPath(filename), "r");

      tiff = BitMiracle.LibTiff.Classic.Tiff.Open(Path.GetFullPath(NewFileName), "w");
      foreach (TiffTag enu in Enum.GetValues(typeof(TiffTag)))
      {
        var val = tiff_org.GetField(enu);
        if (val != null & enu != TiffTag.EXTRASAMPLES)
          tiff.SetField(enu, val[0]);
      }

      for (int i = 0; i < tiff_org.GetTagListCount(); i++)
      {
        int k = tiff_org.GetTagListEntry(i);
        var ff = tiff_org.FindFieldInfo((TiffTag)k, TiffType.ANY);
        tiff.MergeFieldInfo(new TiffFieldInfo[] { ff }, 1);
        var val = tiff_org.GetField((TiffTag)tiff_org.GetTagListEntry(i));
        tiff.SetField((TiffTag)k, val[0], val[1]);
      }

      var val2 = tiff_org.GetField((TiffTag)33922)[1].ToDoubleArray();
      XOrigin = val2[3];
      YOrigin = val2[4]; //Upper basegrid assumes Lower
      val2 = tiff_org.GetField((TiffTag)33550)[1].ToDoubleArray();
      GridSize = val2[0];
      GridSize = val2[1];
      NumberOfColumns = tiff_org.GetField(TiffTag.IMAGEWIDTH)[0].ToInt();
      NumberOfRows = tiff_org.GetField(TiffTag.IMAGELENGTH)[0].ToInt();

      //Shift YOrigin to lower left
      YOrigin -= GridSize * NumberOfRows;
      scanline = new byte[tiff_org.ScanlineSize()];
      bits = scanline.Count() / NumberOfColumns;
      ScanLineCache = new Dictionary<int, byte[]>();




    }