/* * Speeded-Up Robust Features (SURF) * http://people.ee.ethz.ch/~surf * * Sample application for feature matching using nearest-neighbor * ratio method. * * BUILD USING "make match.ln". * * Author: Andreas Ess * * Copyright (2006): ETH Zurich, Switzerland * Katholieke Universiteit Leuven, Belgium * All rights reserved. * * For details, see the paper: * Herbert Bay,  Tinne Tuytelaars,  Luc Van Gool, *  "SURF: Speeded Up Robust Features" * Proceedings of the ninth European Conference on Computer Vision, May 2006 * * Permission to use, copy, modify, and distribute this software and * its documentation for educational, research, and non-commercial * purposes, without fee and without a signed licensing agreement, is * hereby granted, provided that the above copyright notice and this * paragraph appear in all copies modifications, and distributions. * * Any commercial use or any redistribution of this software * requires a license from one of the above mentioned establishments. * * For further details, contact Andreas Ess (aess@vision.ee.ethz.ch). */#include <vector>#include <string>#include <iostream>#include <fstream>#include <cmath>#include "ipoint.h"// Define to compile with PGM output#define GRAPHICS#ifdef GRAPHICS#include "image.h"#include "imload.h"#endifusing namespace std;using namespace surf;// Length of descriptor vector, ugly, global variableint vlen;// Calculate square distance of two vectorsdouble distSquare(double *v1, double *v2, int n) {	double dsq = 0.;	while (n--) {		dsq += (*v1 - *v2) * (*v1 - *v2);		v1++;		v2++;	}	return dsq;}// Find closest interest point in a list, given one interest pointint findMatch(const Ipoint& ip1, const vector< Ipoint >& ipts) {	double mind = 1e100, second = 1e100;	int match = -1;	for (unsigned i = 0; i < ipts.size(); i++) {		// Take advantage of Laplacian to speed up matching		if (ipts[i].laplace != ip1.laplace)			continue;		double d = distSquare(ipts[i].ivec, ip1.ivec, vlen);		if (d < mind) {			second = mind;			mind = d;			match = i;		} else if (d < second) {			second = d;		}	}	if (mind < 0.5 * second)		return match;	return -1;}// Find all possible matches between two imagesvector< int > findMatches(const vector< Ipoint >& ipts1, const vector< Ipoint >& ipts2) {	vector< int > matches(ipts1.size());	int c = 0;	for (unsigned i = 0; i < ipts1.size(); i++) {		int match = findMatch(ipts1[i], ipts2);		matches[i] = match;		if (match != -1) {			cout << " Matched feature " << i << " in image 1 with feature "				<< match << " in image 2." << endl;			c++;		}	}	cout << " --> Matched " << c << " features of " << ipts1.size() << " in image 1." << endl;	return matches;}// Load the interest points from a regular ASCII filevoid loadIpoints(string sFileName, vector< Ipoint >& ipts) {	ifstream ipfile(sFileName.c_str());	if( !ipfile ) {		cerr << "ERROR in loadIpoints(): "			<< "Couldn't open file '" << sFileName.c_str() << "'!" << endl;		return;	}	// Load the file header	unsigned count;	ipfile >> vlen >> count;	// create a new interest point vector	ipts.clear();	ipts.resize(count);	// Load the interest points in Mikolajczyk's format	for (unsigned n = 0; n < count; n++) {		// circular regions with diameter 5 x scale		float x, y, a, b, c;		// Read in region data, though not needed for actual matching		ipfile >> x >> y >> a >> b >> c;		float det = sqrt((a-c)*(a-c) + 4.0*b*b);		float e1 = 0.5*(a+c + det);		float e2 = 0.5*(a+c - det);		float l1 = (1.0/sqrt(e1));		float l2 = (1.0/sqrt(e2));		float sc = sqrt( l1*l2 );		ipts[n].x = x;		ipts[n].y = y;		ipts[n].scale = sc/2.5;		// Read in Laplacian		ipfile >> ipts[n].laplace;		// SURF makes Laplacian part of descriptor, so skip it..		ipts[n].ivec = new double[vlen - 1];		for (unsigned j = 0; j < vlen - 1; j++)			ipfile >> ipts[n].ivec[j];	}}void drawLine(Image *im, int x1, int y1, int x2, int y2) {	if ((x1 < 0 && x2 < 0) || (y1 < 0 && y2 < 0) ||	    (x1 >= im->getWidth() && x2 >= im->getWidth()) ||            (y1 >= im->getHeight() && y2 >= im->getHeight()))		return;	bool steep = std::abs(y2 - y1) > std::abs(x2 - x1);	if (steep) {		int t;		t = x1;		x1 = y1;		y1 = t;		t = y2;		y2 = x2;		x2 = t;	}	if (x1 > x2) {		// Swap points		int t;		t = x1;		x1 = x2;		x2 = t;		t = y1;		y1 = y2;		y2 = t;	}	int deltax = x2 - x1;	int deltay = std::abs(y2 - y1);	int error = 0;	int y = y1;	int ystep = y1 < y2 ? 1 : -1;	for (int x = x1; x < x2; x++) {		if (steep) {			if (x >= 0 && y >= 0 && y < im->getWidth() && x < im->getHeight())				im->setPix(y, x, 1);		} else {			if (x >= 0 && y >= 0 && x < im->getWidth() && y < im->getHeight())				im->setPix(x, y, 1);		}		error += deltay;		if (2 * error > deltax) {			y += ystep;			error -= deltax;		}	}}void drawCross(Image *im, int x, int y, int s = 5) {	for (int x1 = x - s; x1 <= x + s; x1++)		im->setPix(x1, y, 1);	for (int y1 = y - s; y1 <= y + s; y1++)		im->setPix(x, y1, 1);}int main(int argc, char **argv) {	Image *im1, *im2;#ifdef GRAPHICS	ImLoad ImageLoader;	vector< Ipoint > ipts1, ipts2;	bool drawc = false;#endif	char ofname[100];	im1 = im2 = NULL;	ofname[0] = 0;	// Read the arguments	int arg = 0;	while (++arg < argc) { 		if (! strcmp(argv[arg], "-k1"))			loadIpoints(argv[++arg], ipts1);		if (! strcmp(argv[arg], "-k2"))			loadIpoints(argv[++arg], ipts2);#ifdef GRAPHICS		if (! strcmp(argv[arg], "-im1"))			im1 = ImageLoader.readImage(argv[++arg]); 		if (! strcmp(argv[arg], "-im2"))			im2 = ImageLoader.readImage(argv[++arg]); 		if (! strcmp(argv[arg], "-o"))			strcpy(ofname, argv[++arg]);		if (! strcmp(argv[arg], "-c"))			drawc = true;#endif	}	if (ipts1.size() == 0 || ipts2.size() == 0) {		cout << "Usage:" << endl;		cout << " match -k1 out1.surf -k2 out2.surf -im1 img1.pgm -im2 img2.pgm -o out.pgm" << endl << endl;		cout << "For each feature in first descriptor file, find best in second according to "			<< "nearest neighbor ratio strategy. Display matches in out.pgm, generated "			<< "from img1.pgm and img2.pgm. Use -c to draw crosses at interest points." << endl;		return 1;	}	vector< int > matches = findMatches(ipts1, ipts2);#ifdef GRAPHICS	if (im1 != NULL && im2 != NULL && ofname[0] != 0) {		Image res(max(im1->getWidth(), im2->getWidth()), im1->getHeight() + im2->getHeight());		for (int x = 0; x < im1->getWidth(); x++)			for (int y = 0; y < im1->getHeight(); y++)				res.setPix(x, y, im1->getPix(x, y));		for (int x = 0; x < im2->getWidth(); x++)			for (int y = 0; y < im2->getHeight(); y++)				res.setPix(x, y + im1->getHeight(), im2->getPix(x, y));		// Draw lines for matches		for (unsigned i = 0; i < matches.size(); i++) {			if (matches[i] != -1) {				drawLine(&res, (int)ipts1[i].x, (int)ipts1[i].y,					(int)ipts2[matches[i]].x, (int)(ipts2[matches[i]].y + im1->getHeight()));			}		}		// Draw crosses at interest point locations		if (drawc) {			for (unsigned i = 0; i < ipts1.size(); i++)				drawCross(&res, (int)ipts1[i].x, (int)ipts1[i].y);			for (unsigned i = 0; i < ipts2.size(); i++)				drawCross(&res, (int)ipts2[i].x, (int)ipts2[i].y + im1->getHeight());		}		ImageLoader.saveImage(ofname, &res);	}#endif		return 0;}