Opencv中的调试断言失败

Question

当我运行代码很容易通过Visual Studio 2015找到图像的轮廓但它看起来像一个表

  

＆＃34; DEBUG ASSERTION FAILED   EXPRESION：块类型有效（header-＆gt; block use）＆＃34;

我不知道如何在很多时候解决问题。 这是我的C ++代码：

int main(int argc, const char * argv[]) {

    cv::Mat image = cv::imread("Lena.png");
    if (!image.data) {
        std::cout << "Image file not found\n";
        return 1;
    }
    //Prepare the image for findContours
    cv::cvtColor(image, image, CV_RGB2GRAY);
    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;
    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);

    return 0;
}