opencv chamfer distance C++ code missing header file - c++

Question

I am trying the compile the following code to compute the chamfer distance. However I get the following error while compiling it. I am using opencv-3.2 on ubuntu 18.04, 64 bit.
fatal error: opencv2/contrib/contrib.hpp: No such file or directory
Synaptic package manager says that libopencv-contrib-dev and libopencv-contrib-3.2 are installed at /usr/include/opencv2 and /usr/lib/x86_64-linux-gnu respectively. I checked for contrib.hpp but found no file or folder named contrib in these locations.
The code for the chamfer distance computation is as below:
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main( int argc, const char** argv )
{
Mat img = imread(argv[1], 0);
Mat tpl = imread(argv[2], 0);
Mat cimg;
cvtColor(img, cimg, CV_GRAY2BGR);
vector<vector<Point> > results;
vector<float> costs;
int best = chamerMatching( img, tpl, results, costs );
return 0;
}
My question is: How to add the correct headers and get the above chamfer distance code working in opencv 3.2?

Answer 1

It looks like the contrib module is not available in OpenCV 3.2. This module was removed in OpenCV 4.0 and is no longer part of the library. If you want to use the Chamfer matching algorithm in your code, you can try using the matchShapes function from the imgproc module instead. This function can be used to compare the shapes of two contours and return a measure of their similarity:
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main( int argc, const char** argv )
{
Mat img = imread(argv[1], 0);
Mat tpl = imread(argv[2], 0);
// Find the contours of the images
vector<vector<Point> > img_contours;
vector<vector<Point> > tpl_contours;
findContours(img, img_contours, RETR_EXTERNAL, CHAIN_APPROX_NONE);
findContours(tpl, tpl_contours, RETR_EXTERNAL, CHAIN_APPROX_NONE);
// Compute the Chamfer distance between the contours
double chamfer = matchShapes(img_contours[0], tpl_contours[0], CHAMFER_DIST_L2, 0);
cout << "Chamfer distance: " << chamfer << endl;
return 0;
}