This program extracts ridges and bifurcations from a fingerprint image.

minutiae.c

/*
 * Programming introduction with the SOD Embedded Image Processing API.
 * Copyright (C) PixLab | Symisc Systems, https://sod.pixlab.io
 */
/*
* Compile this file together with the SOD embedded source code to generate
* the executable. For example:
*
*  gcc sod.c minutiae.c -lm -Ofast -march=native -Wall -std=c99 -o sod_img_proc
*  
* Under Microsoft Visual Studio (>= 2015), just drop `sod.c` and its accompanying
* header files on your source tree and you're done. If you have any trouble
* integrating SOD in your project, please submit a support request at:
* https://sod.pixlab.io/support.html
*/
/*
* This simple program is a quick introduction on how to embed and start
* experimenting with SOD without having to do a lot of tedious
* reading and configuration.
*
* Make sure you have the latest release of SOD from:
*  https://pixlab.io/downloads
* The SOD Embedded C/C++ documentation is available at:
*  https://sod.pixlab.io/api.html
*/
#include <stdio.h>
#include "sod.h"
/*
 * This program extracts ridges and bifurcations from a fingerprint image.
 *
 * Minutiae extraction is applied to skeletonized fingerprint image
 *
 * The target image must be binary (i.e. images whose pixels have only two possible intensity
 * value mostly black or white). You can obtain a binary image via sod_canny_edge_image(),
 * sod_otsu_binarize_image(), sod_binarize_image() or sod_threshold_image().
 *
 * More information about this process can be found at https://sod.pixlab.io/c_api/sod_minutiae.html
 */
int main(int argc, char *argv[])
{
	/* Input image (pass a path or use the test image shipped with the samples ZIP archive)
	*
	*  Minutiae extraction is applied to skeletonized fingerprint image.
	*/
	const char *zInput = argc > 1 ? argv[1] : "./fingerprint/fp_whole.pgm";
	/* Processed output image path */
	const char *zOut = argc > 2 ? argv[2] : "./out_fp.png";
	/* Load the input image in the grayscale colorspace */
	sod_img imgIn = sod_img_load_from_file(zInput, SOD_IMG_GRAYSCALE/* single channel colorspace (gray)*/);
	if (imgIn.data == 0) {
		/* Invalid path, unsupported format, memory failure, etc. */
		puts("Cannot load input image..exiting");
		return 0;
	}
	/* Binarize the input image before the thinning process */
	sod_img binImg = sod_threshold_image(imgIn, 0.5);

	/* Perform Hilditch thinning on this binary image. */
	sod_img hildImg = sod_hilditch_thin_image(binImg);

	/* Perform extraction of minutiae candidates in  fingerprint image */
	int total, np1, np2;
	sod_img imgOut = sod_minutiae(hildImg, &total, &np1, &np2);
	printf("total number of BLACK points = %d\n", total);
	printf("number of ending points = %d\n", np1);
	printf("number of bifurcations = %d\n\n", np2);

	/* Finally save our processed image to the specified path */
	sod_img_save_as_png(imgOut, zOut);
	/* Cleanup */
	sod_free_image(imgIn);
	sod_free_image(binImg);
	sod_free_image(hildImg);
	sod_free_image(imgOut);
	return 0;
}

This program extracts ridges and bifurcations from a fingerprint image.
Minutiae extraction is applied to skeletonized fingerprint image

The target image must be binary (i.e. images whose pixels have only two possible intensity
value mostly black or white). You can obtain a binary image via sod_canny_edge_image(),
sod_otsu_binarize_image(), sod_binarize_image() or sod_threshold_image().

More information about this process can be found at https://sod.pixlab.io/c_api/sod_minutiae.html