sod_minutiae()- SOD C/C++ API

SOD C/C++ API Reference - Image Processing

Syntax

sod_img sod_minutiae(sod_img input, int *pTotal, int *pEp, int *pBp);

Description

Extracts ridges and bifurcations from a fingerprint image. Minutiae extraction is applied to skeletonized fingerprint image obtained from sod_hilditch_thin_image().
A typical input picture should look like the following after processing:

Input grayscale fingerprint

sod_minutiae() Output

According to Wikipedia, Minutiae are major features of a fingerprint, using which comparisons of one print with another can be made. Minutiae include:

Ridge ending – the abrupt end of a ridge.
Ridge bifurcation – a single ridge that divides into two ridges.
Ridge trifurcation – a single ridge that divides into three ridges.
Short ridge, or independent ridge – a ridge that commences, travels a short distance and then ends.
Island – a single small ridge inside a short ridge or ridge ending that is not connected to all other ridges.
Ridge enclosure – a single ridge that bifurcates and reunites shortly afterward to continue as a single ridge.
Spur – a bifurcation with a short ridge branching off a longer ridge.
Crossover or bridge – a short ridge that runs between two parallel ridges.
Delta – a Y-shaped ridge meeting.
Core – circle in the ridge pattern.
Arch - a U-shape in the ridge pattern.

Parameters

sod_img input

The input image to be processed which must be skeletonized via a prior successful call to sod_hilditch_thin_image(). The image can be loaded from disk using sod_img_load_from_file(), from memory (i.e. network socket) via sod_img_load_from_mem() or dynamically created via sod_make_image().

int *pTotal

OUT/OPTIONAL: If set, this will hold the total number of black points.

int *pEp

OUT/OPTIONAL: If set, this will hold the total number of ending points.

int *pBp

OUT/OPTIONAL: If set, this will hold the total number of bifurcations.

Return Value

Processed image is returned in an instance of the sod_img object. if something goes wrong during processing, then an empty image is returned via sod_make_empty_image(). Once done, you must release the memory allocated to this object via sod_free_image() to avoid memory leaks.

Example

Checkout the introduction course, the C/C++ samples on the download page or refer to the SOD Github Repository.