OpenCV C++ VS2010: FindContours throws exception - c++

Question

Hi I am trying to run a simple OpenCV program to detect contours in a picture. however, findcontours keeps throwing exceptions.
here is my code:
#include "stdafx.h"
#include <stdio.h>
#include <iostream>
#include <opencv2\opencv.hpp>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/nonfree/nonfree.hpp"
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;
/** #function main */
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <math.h>
#include <string.h>
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, const char * argv[]) {
IplImage* img = cvLoadImage("C:\\Users\\310217955\\Documents\\Visual Studio 2010\\Projects\\aviTest\\Debug\\Pictures\\Capture.jpg");
cv::Mat image = cv::cvarrToMat(img);
if (!image.data) {
std::cout << "Image file not found\n";
return 1;
}
//Prepare the image for findContours
cv::cvtColor(image, image, CV_BGR2GRAY);
cv::threshold(image, image, 128, 255, CV_THRESH_BINARY);
//Find the contours. Use the contourOutput Mat so the original image doesn't get overwritten
//std::vector<std::vector<cv::Point> > contours;
vector<cv::Mat> contours;
cv::Mat contourOutput = image.clone();
cv::findContours( contourOutput, contours, CV_RETR_LIST, CV_CHAIN_APPROX_NONE );
//Draw the contours
cv::Mat contourImage(image.size(), CV_8UC3, cv::Scalar(0,0,0));
cv::Scalar colors[3];
colors[0] = cv::Scalar(255, 0, 0);
colors[1] = cv::Scalar(0, 255, 0);
colors[2] = cv::Scalar(0, 0, 255);
for (size_t idx = 0; idx < contours.size(); idx++) {
cv::drawContours(contourImage, contours, idx, colors[idx % 3]);
}
cv::imshow("Input Image", image);
cvMoveWindow("Input Image", 0, 0);
cv::imshow("Contours", contourImage);
cvMoveWindow("Contours", 200, 0);
cv::waitKey(0);
system("PAUSE");
return 0;
}
here is an image of the exception:
how can I get around this? is there a dll file im missing or some settings i need to resolve?
I did the following changes to the code
vector<Vec4i> hierarchy;
findContours( contourOutput, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE);
but now I get the following exception:

Answer 1

Well your code works perfectly fine.I only commented out the header files stdafx.h and nonfree.hpp in my project file . This is the output i gotenter image description here
Make sure you providing the correct path to the input img or paste your input image in your visual studio solution directory and just load the image directly.
The problem may be with one of the modules. I would suggest reinstalling opencv(try downloading the latest version) and try again. Make sure you are adding xyzd.lib files like opencv_highgui330d.lib opencv_imgproc330d.lib
in linker>>Input>> additional dependencies. the version might differ for you.
Hope this helps you!