CurveMatching

Matching 2D curves in OpenCV using scale space transform.

See http://www.morethantechnical.com/2012/12/26/2d-curve-matching-w-code/ for details.

Sample Usage

vector<Point> a,b;

//Get curve from image
GetCurveForImage("binary_image_with_silhuette.png", a, false);
ResampleCurve(a, a, 200, false);

vector<Point2d> a_p2d;
ConvertCurve(a, a_p2d);

//rotate and scale
Scalar meanpt = mean(a);
Mat_<double> trans_to = getRotationMatrix2D(Point2f(meanpt[0],meanpt[1]), 5, 0.65);

//create target curve from original curve
vector<Point2d> b_p2d;
cv::transform(a_p2d,b_p2d,trans_to);

ConvertCurve(b_p2d, b);


//Compare curves
int a_len,a_off,b_len,b_off;
double compare_score;
CompareCurvesUsingSignatureDB(a, 
			  b,
			  a_len,
			  a_off,
			  b_len,
			  b_off,
			  compare_score
			  );

vector<Point2d> a_subset(a.begin() + _a_off, a.begin() + _a_off + _a_len);
vector<Point2d> b_subset(b.begin() + _b_off, b.begin() + _b_off + _b_len);

ResampleCurve(a_subset, a_subset, 200, true);
ResampleCurve(b_subset, b_subset, 200, true);

Mat trans = Find2DRigidTransform(a_subset, b_subset);
cout << trans << endl;
vector<Point2d> a_trans;
cv::transform(a_subset,a_trans,trans);

Compile

mkdir build
cd build
cmake ..
make