ISO template minutiae

ISO template minutiae, a part of algorithm transparency, are minutiae obtained from ISO 19794-2 template during conversion. Minutia positions and fingerprint size are normalized to 500dpi. See ISO template metadata for original DPI and fingerprint size. ISO template minutiae, like shuffled minutiae, are an input to edge table and edge hash. They are used to pick root pairs, construct pairings, and compute score.

KeywordSuffixZip
iso-minutiae.json002-iso-minutiae.json

Visualization

Visualization of ISO template minutiae was constructed from this stage's json data. Visualization itself is not part of transparency data.

Fingerprint minutiae, blue endings and green bifurcations, from ISO 19794-2 template
Minutiae from ISO 19794-2 template. Endings are blue, bifurcations are green.

Json

Structure of the json data is the same as for skeleton minutiae except that width, height, and minutia positions (x, y) are scaled according to DPI information in ISO template metadata since ISO template conversion skips feature extraction including image scaling. All coordinates in this json data are in coordinate system of a scaled 500dpi version of the ISO 19794-2 template rather than the coordinate system described by the original ISO template metadata.

Example: 002-iso-minutiae.json

{
  "width": 224,
  "height": 288,
  "minutiae": [
    {
      "x": 78,
      "y": 13,
      "direction": 5.546874528994478,
      "type": "ending"
    },
    {
      "x": 128,
      "y": 13,
      "direction": 5.767767762450011,
      "type": "bifurcation"
    },
    {
      "x": 145,
      "y": 32,
      "direction": 6.037748381117884,
      "type": "ending"
    },
    {
      "x": 65,
      "y": 59,
      "direction": 2.258019719767664,
      "type": "bifurcation"
    },
    {
      "x": 205,

... skipped 174 lines ...

      "y": 264,
      "direction": 5.399612373357457,
      "type": "ending"
    },
    {
      "x": 112,
      "y": 269,
      "direction": 6.062292073724054,
      "type": "bifurcation"
    },
    {
      "x": 45,
      "y": 270,
      "direction": 2.3071071049800045,
      "type": "ending"
    },
    {
      "x": 149,
      "y": 273,
      "direction": 3.8288160465625602,
      "type": "bifurcation"
    },
    {
      "x": 194,
      "y": 279,
      "direction": 4.025165587411923,
      "type": "ending"
    }
  ]
}