Hi ! I'm trying to calculate eccentricity of finded conturs. I's works with circles and elips ( not ideally ), but gives extremele low raiting to lines with angle like this '/' ( I draw some images in paint :) ) And for line with angle like this '\' it's gives extremele hige rate.
double getEccentricity(Moments &mu){
double bigSqrt = sqrt( ( mu.m20 - mu.m02 ) * ( mu.m20 - mu.m02 ) + 4 * mu.m11 * mu.m11 );
return (double) ( mu.m20 + mu.m02 + bigSqrt ) / ( mu.m20 + mu.m02 - bigSqrt );
}
void tryElongation(){
Mat img;
img = imread("5.jpg");
cvtColor(img, img, CV_RGB2GRAY);
close( &img );
imshow( "img", img );
RNG rng(12345);
Mat drawing = Mat::zeros( img.size(), CV_8UC3 );
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
findContours( img, contours, hierarchy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_TC89_L1, Point(0, 0) );
for( int i = 0; i< contours.size(); i++ ){
//show conturs
Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
drawContours( drawing, contours, i, color, 2, 8, hierarchy, 0, Point() );
Moments mu = moments( contours[i] , 1 ); // bool 1 ???
double eccentricity = getEccentricity( mu );
cout << eccentricity << " " ;
}
namedWindow( "Contours", CV_WINDOW_AUTOSIZE );
imshow( "Contours", drawing );
cv::waitKey(2000);
}