Shuffled minutiae

Shuffled minutiae, a part of algorithm transparency, are the result of the last filter applied to skeleton minutiae after top minutiae filter. Shuffling doesn't remove any minutiae. It just changes their order pseudo-randomly. The random ordering is consistent, which means that running feature extractor on the same image twice results in exactly the same fingerprint template. Minutia shuffling is done to improve quality of picked roots. Shuffled minutiae, being the last stage of minutia processing, are an input to edge table and edge hash. They are used to pick roots, construct pairings, and compute score.

Visualization

Visualization of shuffled minutiae was constructed from this stage's CBOR data with original fingerprint in the background. Visualization itself is not part of transparency data.

Format

Format of shuffled minutiae is identical to skeleton minutiae.

Example: 042-shuffled-minutiae.cbor

{
  "size": {
    "x": 388,
    "y": 374
  },
  "minutiae": [
    {
      "position": {
        "x": 74,
        "y": 136
      },
      "direction": 1.9513026,
      "type": "ENDING"
    },
    {
      "position": {
        "x": 80,
        "y": 156
      },
      "direction": 1.9936502,
      "type": "ENDING"
    },
    "... skipped 42 items ...",
    {
      "position": {
        "x": 194,
        "y": 93
      },
      "direction": 0.6000502,
      "type": "ENDING"
    },
    {
      "position": {
        "x": 265,
        "y": 207
      },
      "direction": 1.670465,
      "type": "BIFURCATION"
    }
  ]
}