Block orientation

SourceAFIS » Algorithm » Transparency » Block orientation

Block orientation, a part of algorithm transparency, contains orientation vector for primary blocks that are within mask. Orientation vector has the same meaning as in pixelwise orientation, from which block orientation is computed during feature extraction by adding up orientation vectors within every block. Block orientation is refined into smoothed orientation.

KeyMIMEFilename in ZIP
block-orientationapplication/cbor014-block-orientation.cbor

Visualization

This visualization was constructed from this stage's binary data mapped onto blocks, masked, and overlaid on the original fingerprint image. Visualization itself is not part of transparency data.

Block orientations on a fingerprint visualized as red sticks oriented parallel to ridges
Block-level ridge orientation.

Format

Block orientation has the same format as pixelwise orientation except that orientation is tracked per primary block rather than per pixel. No orientation is computed for blocks outside the mask.

Example: 014-block-orientation.cbor

{
  "width": 26,
  "height": 25,
  "vectors": [
    0.0,
    0.0,
    "... skipped 1,296 items in range -472 to 641 ...",
    0.0,
    0.0
  ]
}