Decoded image

SourceAFIS » Algorithm » Transparency » Decoded image

Decoded image, a part of algorithm transparency, is the original fingerprint image used for feature extraction (template construction). Decoded image contains unchanged pixels as deserialized by SourceAFIS except that pixel values are mapped to floating-point range between 0 and 1. It is an input to image scaling.

KeyMIMEFilename in ZIP
decoded-imageapplication/cbor002-decoded-image.cbor

Visualization

The following fingerprint image can be reconstructed from this stage's binary data. Visualization itself is not part of transparency data.

Black fingerprint image on white background
Original fingerprint image as decoded by SourceAFIS.

Format

Decoded image is a matrix (2-dimensional array) of floating-point numbers, each representing pixel darkness in range 0 (white) to 1 (black). It is encoded in CBOR:

Example: 002-decoded-image.cbor

{
  "width": 388,
  "height": 374,
  "cells": [
    0.0039215686274510775,
    0.0039215686274510775,
    "... skipped 145,108 items in range 0.00392 to 0.996 ...",
    0.0039215686274510775,
    0.07058823529411773
  ]
}