Inner mask

SourceAFIS » Algorithm » Transparency » Inner mask

Inner mask, a part of algorithm transparency, is computed during feature extraction by shrinking pixel mask. It represents inner fingerprint area, somewhat away from fingerprint border. It is used for inner minutiae filtering.

Key	MIME	Filename in ZIP
`inner-mask`	`application/cbor`	`021-inner-mask.cbor`

Visualization

The following visualization was created from this stage's binary data overlaid on top of the original fingerprint image. Visualization itself is not part of transparency data.

Fingerprint image with interior area highlighted in yellow color — Inner mask region is shown as light yellow.

Format

Inner mask format is the same as for filtered mask except that matrix cells represent individual pixels rather than blocks.

Example: 021-inner-mask.cbor

{
  "width": 388,
  "height": 374,
  "cells": [
    false,
    false,
    "... skipped 145,108 items ...",
    false,
    false
  ]
}