OpenCV Assertion Fehler beim Berechnen von Momenten

Question

Ich habe versucht, this Tutorial zu verwenden, um Momente dieser pic zu finden. Aber ich bekomme immer Bestätigung fehlgeschlagen Fehler in Zeile

mu[i] = moments(contours, false); 

Was mache ich hier falsch?

#include "opencv2/highgui/highgui.hpp" 
#include "opencv2/core/core.hpp" 
#include "opencv2/imgproc/imgproc.hpp" 
#include <iostream> 
#include <cmath> 
#include <stdio.h> 
#include <stdlib.h> 
using namespace cv; 
using namespace std; 

int main(int, char *[]) { 
    cv::Mat roi = cv::imread("ROI.jpg"); 
    cv::Mat kontury = roi; 
    cv::cvtColor(roi, kontury, CV_RGB2GRAY); 
    vector<vector<Point> > contours; 
    vector<Vec4i> hierarchy; 
    findContours(kontury, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0)); 

    /// Get the moments 
    vector<Moments> mu(contours.size()); 
    for (int i = 0; i < contours.size(); i++) 
    { 
     mu[i] = moments(contours, false); 
    } 

    /// Get the mass centers: 
    vector<Point2f> mc(contours.size()); 
    for (int i = 0; i < contours.size(); i++) 
    { 
     mc[i] = Point2f(mu[i].m10/mu[i].m00, mu[i].m01/mu[i].m00); 
    } 

    /// Calculate the area with the moments 00 and compare with the result of the OpenCV function 
    Mat drawing = Mat::zeros(roi.size(), CV_8UC3); 

    printf("\t Info: Area and Contour Length \n"); 
    for (int i = 0; i< contours.size(); i++) 
    { 
     printf(" * Contour[%d] - Area (M_00) = %.2f - Area OpenCV: %.2f - Length: %.2f \n", i, mu[i].m00, contourArea(contours[i]), arcLength(contours[i], true)); 
     Scalar color = Scalar(rand() % 256, rand() % 256, rand() % 256); 
     drawContours(drawing, contours, i, color, 2, 8, hierarchy, 0, Point()); 
     circle(drawing, mc[i], 4, color, -1, 8, 0); 
    } 

    cv::waitKey(-1); 
} 

Answer 1

Die Eingabe von moments sollte ein std::vector<cv::Point>, nicht std::vector<std::vector<cv::Point>> sein. Sie haben gerade vergessen, die i-te Kontur auszuwählen:

mu[i] = moments(contours[i], false); 
//      ^^^