Meta Information Generation

{
  "id": "NNNNN"
  {
    "modality": "XXX",
    {
      "slice": "N"
      {
        "freehand": [[x11 y11],
                     [x12 y12],
                        ...
                     [x1n y1n]],
                    [[x21 y21],
                     [x22 y22],
                        ...
                     [x2n y2n]]
      }
    }
    "modality": "XXX",
    {
      "slice": ""
      {
        "freehand": [[x11 y11],
                     [x12 y12],
                        ...
                     [x1n y1n]],
                    [[x21 y21],
                     [x22 y22],
                        ...
                     [x2n y2n]]
      }
    }
  }
}