Minutiae feature extraction for fingerprint images

samples/minutiae.c

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+/*
+ * 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;
+}