findContours returns assertion failed - c++

Question

Seems that the findContours function has been returning some assertion fails with Visual Studios C++ 2012. I've made sure that all my include directories were fine.
void track (Mat input_video, Mat &output_video)
{
Mat temp;
input_video.copyTo(temp);
vector<vector<cv::Point> > contours;
vector<Vec4i> hierarchy;
findContours(temp, contours, hierarchy, CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);
//Only search through the most external layer.
for (int i=0; i>=0; i=hierarchy[i][0])
{
Moments moment = moments((Mat) contours[i]);
double area= moment.m00;
double xmc= moment.m10;
double ymc= moment.m01;
double x= xmc/area;
double y= ymc/area;
circle(output_video, Point(x,y), 3, Scalar(0,255,255));
}
}
EDIT:
The rest of my code if you may need it:
#include "opencv2/opencv.hpp"
#include <iostream>
using namespace std;
using namespace cv;
//This function threshold the HSV image and create a binary image
Mat GetThresholdedImage(Mat imgHSV, int huemin, int satmin, int valmin, int huemax, int satmax, int valmax)
{
//Size s= imgHSV->size();
Mat imgThresh(imgHSV.size().height, imgHSV.size().width, CV_8U);
//returns matrix that contains all values within the given HSV range.
inRange(imgHSV, Scalar(huemin,satmin,valmin), Scalar(huemax,satmax,valmax), imgThresh);
return imgThresh;
}
Mat morph(Mat imgThresh)
{
Mat erode_element= getStructuringElement(MORPH_RECT, Size(3,3));
Mat dilate_element= getStructuringElement(MORPH_RECT, Size(8,8));
erode(imgThresh, imgThresh, erode_element);
erode(imgThresh, imgThresh, erode_element);
dilate(imgThresh, imgThresh, dilate_element);
return imgThresh;
}
void track (Mat input_video, Mat &output_video)
{
Mat temp;
input_video.copyTo(temp);
vector< vector<Point> > contours;
cerr<< contours.size();
vector<Vec4i> hierarchy;
findContours(temp, contours, hierarchy, CV_RETR_CCOMP, CV_CHAIN_APPROX_SIMPLE);
cerr<<contours.size();
//Only search through the most external layer.
for (int i=0; i>=0; i=hierarchy[i][0])
{
Moments moment = moments((Mat) contours[i]);
double area= moment.m00;
double xmc= moment.m10;
double ymc= moment.m01;
double x= xmc/area;
double y= ymc/area;
circle(output_video, Point(x,y), 3, Scalar(0,255,255));
}
}
int main()
{
VideoCapture capture(0);
if(!capture.isOpened()){
cerr<< "Capture failed";
return -1;
}
Mat frame;
namedWindow("Original");
namedWindow("Binary");
//Create slider for adjustments...
namedWindow("Adjustments");
int huemin= 0, satmin= 0, valmin= 0;
int huemax= 256, satmax= 256, valmax= 256;
createTrackbar("Min Hue", "Adjustments", &huemin, 256);
createTrackbar("Max Hue", "Adjustments", &huemax, 256);
createTrackbar("Min Saturation", "Adjustments", &satmin, 256);
createTrackbar("Max Saturation", "Adjustments", &satmax, 256);
createTrackbar("Min Value", "Adjustments", &valmin, 256);
createTrackbar("Max Value", "Adjustments", &valmax, 256);
//iterate through each frames of the video
while(true)
{
//Grabs each frame from video to be processed.
capture>> frame;
//Error checks and breaks if the grab failed.
if(!frame.data)
{
cerr<< "Failed to grab frame\n";
break;
}
//Apply a Gaussian Blur kernel.
//GaussianBlur(frame, frame, Size(3,3), 3, 3, 4);
Mat imgHSV(frame.size(), CV_8UC3);
cvtColor(frame, imgHSV, CV_BGR2HSV, 0); //Change the color format from BGR to HSV
Mat imgThresh = GetThresholdedImage(imgHSV, huemin, satmin, valmin, huemax, satmax, valmax);
//GaussianBlur(imgThresh, imgThresh, Size(5,5), 3, 3, 4); //smooth the binary image using Gaussian kernel
imgThresh= morph(imgThresh);
track(imgThresh, frame);
imshow("Binary", imgThresh);
imshow("Original", frame);
int key = waitKey(30);
//If 'ESC' is pressed, break the loop
if(key==27 ) break;
}
destroyAllWindows();
//cvReleaseCapture(&capture);
return 0;
}

Answer 1

Eugene, I encountered the same problem. try to add "cv::imshow("im", output_video);"
as mentioned in - OpenCV findContours causes Debug Assertion Failed at return