106 lines
No EOL
4.5 KiB
C++
106 lines
No EOL
4.5 KiB
C++
// This file is part of OpenCV project.
|
|
// It is subject to the license terms in the LICENSE file found in the top-level directory
|
|
// of this distribution and at http://opencv.org/license.html
|
|
|
|
#include "opencv2/calib3d.hpp"
|
|
#include "opencv2/highgui.hpp"
|
|
#include "opencv2/imgproc.hpp"
|
|
|
|
#include <vector>
|
|
#include <iostream>
|
|
|
|
using namespace cv;
|
|
|
|
int main(int args, char** argv) {
|
|
std::string img_name1, img_name2;
|
|
if (args < 3) {
|
|
CV_Error(Error::StsBadArg,
|
|
"Path to two images \nFor example: "
|
|
"./epipolar_lines img1.jpg img2.jpg");
|
|
} else {
|
|
img_name1 = argv[1];
|
|
img_name2 = argv[2];
|
|
}
|
|
|
|
Mat image1 = imread(img_name1);
|
|
Mat image2 = imread(img_name2);
|
|
Mat descriptors1, descriptors2;
|
|
std::vector<KeyPoint> keypoints1, keypoints2;
|
|
|
|
Ptr<SIFT> detector = SIFT::create();
|
|
detector->detect(image1, keypoints1);
|
|
detector->detect(image2, keypoints2);
|
|
detector->compute(image1, keypoints1, descriptors1);
|
|
detector->compute(image2, keypoints2, descriptors2);
|
|
|
|
FlannBasedMatcher matcher(makePtr<flann::KDTreeIndexParams>(5), makePtr<flann::SearchParams>(32));
|
|
|
|
// get k=2 best match that we can apply ratio test explained by D.Lowe
|
|
std::vector<std::vector<DMatch>> matches_vector;
|
|
matcher.knnMatch(descriptors1, descriptors2, matches_vector, 2);
|
|
|
|
std::vector<Point2d> pts1, pts2;
|
|
pts1.reserve(matches_vector.size()); pts2.reserve(matches_vector.size());
|
|
for (const auto &m : matches_vector) {
|
|
// compare best and second match using Lowe ratio test
|
|
if (m[0].distance / m[1].distance < 0.75) {
|
|
pts1.emplace_back(keypoints1[m[0].queryIdx].pt);
|
|
pts2.emplace_back(keypoints2[m[0].trainIdx].pt);
|
|
}
|
|
}
|
|
|
|
std::cout << "Number of points " << pts1.size() << '\n';
|
|
|
|
Mat inliers;
|
|
const auto begin_time = std::chrono::steady_clock::now();
|
|
const Mat F = findFundamentalMat(pts1, pts2, RANSAC, 1., 0.99, 2000, inliers);
|
|
std::cout << "RANSAC fundamental matrix time " << static_cast<int>(std::chrono::duration_cast<std::chrono::microseconds>
|
|
(std::chrono::steady_clock::now() - begin_time).count()) << "\n";
|
|
|
|
Mat points1 = Mat((int)pts1.size(), 2, CV_64F, pts1.data());
|
|
Mat points2 = Mat((int)pts2.size(), 2, CV_64F, pts2.data());
|
|
vconcat(points1.t(), Mat::ones(1, points1.rows, points1.type()), points1);
|
|
vconcat(points2.t(), Mat::ones(1, points2.rows, points2.type()), points2);
|
|
|
|
RNG rng;
|
|
const int circle_sz = 3, line_sz = 1, max_lines = 300;
|
|
std::vector<int> pts_shuffle (points1.cols);
|
|
for (int i = 0; i < points1.cols; i++)
|
|
pts_shuffle[i] = i;
|
|
randShuffle(pts_shuffle);
|
|
int plot_lines = 0, num_inliers = 0;
|
|
double mean_err = 0;
|
|
for (int pt : pts_shuffle) {
|
|
if (inliers.at<uchar>(pt)) {
|
|
const Scalar col (rng.uniform(0,256), rng.uniform(0,256), rng.uniform(0,256));
|
|
const Mat l2 = F * points1.col(pt);
|
|
const Mat l1 = F.t() * points2.col(pt);
|
|
double a1 = l1.at<double>(0), b1 = l1.at<double>(1), c1 = l1.at<double>(2);
|
|
double a2 = l2.at<double>(0), b2 = l2.at<double>(1), c2 = l2.at<double>(2);
|
|
const double mag1 = sqrt(a1*a1 + b1*b1), mag2 = (a2*a2 + b2*b2);
|
|
a1 /= mag1; b1 /= mag1; c1 /= mag1; a2 /= mag2; b2 /= mag2; c2 /= mag2;
|
|
if (plot_lines++ < max_lines) {
|
|
line(image1, Point2d(0, -c1/b1),
|
|
Point2d((double)image1.cols, -(a1*image1.cols+c1)/b1), col, line_sz);
|
|
line(image2, Point2d(0, -c2/b2),
|
|
Point2d((double)image2.cols, -(a2*image2.cols+c2)/b2), col, line_sz);
|
|
}
|
|
circle (image1, pts1[pt], circle_sz, col, -1);
|
|
circle (image2, pts2[pt], circle_sz, col, -1);
|
|
mean_err += (fabs(points1.col(pt).dot(l2)) / mag2 + fabs(points2.col(pt).dot(l1) / mag1)) / 2;
|
|
num_inliers++;
|
|
}
|
|
}
|
|
std::cout << "Mean distance from tentative inliers to epipolar lines " << mean_err/num_inliers
|
|
<< " number of inliers " << num_inliers << "\n";
|
|
// concatenate two images
|
|
hconcat(image1, image2, image1);
|
|
const int new_img_size = 1200 * 800; // for example
|
|
// resize with the same aspect ratio
|
|
resize(image1, image1, Size((int) sqrt ((double) image1.cols * new_img_size / image1.rows),
|
|
(int)sqrt ((double) image1.rows * new_img_size / image1.cols)));
|
|
|
|
imshow("epipolar lines, image 1, 2", image1);
|
|
imwrite("epipolar_lines.png", image1);
|
|
waitKey(0);
|
|
} |