Quickly capture N frames and continue with live feed

edit

I would like to capture N number of images process them and do something with live feed from the camera. I start camera, capture 30 frames and store them in a Mat vector. Now when I try to access or process the vector I am getting runtime error. I am using pointgray camera. I think I am missing something really basic. Kindly guide me what could be wrong?

      #include <opencv2\highgui\highgui.hpp>
      #include <opencv2\core\core.hpp>
      #include <opencvlibpath.h>
      #include <FlyCapture2.h>
      #include <vector>

      using namespace cv;
      using namespace FlyCapture2;
      using namespace std;

        const static int NUMBER_OF_FRAME_CAPTURE = 30;
       const static int SENSITIVITY_VALUE = 60;
       const static int BLUR_SIZE = 50;


       //I would like to execute this function after quickly capturing 30 frames
        void getThresholdImage(vector<Mat>  &framesToProcess, vector<Mat> &thresholdImages)
       {
      vector<Mat> grayImage;

for (int i = 0; i < framesToProcess.size(); i++)
{
    Mat tempMatImage, tempGrayImage;

    resize(framesToProcess[i], tempMatImage, Size(600, 800));
    cvtColor(tempMatImage, tempGrayImage, COLOR_BGR2GRAY);
    grayImage.push_back(tempGrayImage);

    if (i > 0)
    {
        Mat tempDifferenceImage, tempThresholdImage;
        absdiff(grayImage[i - 1], grayImage[i], tempDifferenceImage);
        threshold(tempDifferenceImage, tempThresholdImage, SENSITIVITY_VALUE, 255, THRESH_BINARY);
        blur(tempThresholdImage, tempThresholdImage, Size(BLUR_SIZE, BLUR_SIZE));
        thresholdImages.push_back(tempThresholdImage);
    }
}
 }

  int main()
 {
Mat cameraFeed;

vector<Image> rawImages;
vector<Mat> framesToProcess;
vector<Mat> thresholdImages;
//vector<point> contourCenters;
vector<Point> LEDPoints;

Camera camera;
Error error;

error = camera.Connect(0);
if (error != PGRERROR_OK)
{
    cout << "Failed to connect to camera" << endl;
    getchar();
    exit(1);
}
error = camera.StartCapture();
if (error == PGRERROR_ISOCH_BANDWIDTH_EXCEEDED)
{
    cout << "Bandwidth exceeded" << endl;
    getchar();
    exit(1);
}
else if (error != PGRERROR_OK)
{
    cout << "Failed to start image capture" << endl;
    getchar();
    exit(1);
}

while (1){

    framesToProcess.clear();
    thresholdImages.clear();
    rawImages.clear();

    //quickly capture 30 images
    for (int i = 0; i < NUMBER_OF_FRAME_CAPTURE; i++)
    {
        Mat currentFrame;
        Image rawImage;
        Error error = camera.RetrieveBuffer(&rawImage);
        if (error != PGRERROR_OK)
        {
            cout << "capture error" << endl;
        }

        // convert to rgb
        Image rgbImage;
        rawImage.Convert(FlyCapture2::PIXEL_FORMAT_BGR, &rgbImage);

        // convert to OpenCV Mat
        unsigned int rowBytes = (double)rgbImage.GetReceivedDataSize() / (double)rgbImage.GetRows();
        currentFrame = Mat(rgbImage.GetRows(), rgbImage.GetCols(), CV_8UC3, rgbImage.GetData(), rowBytes);
        framesToProcess.push_back(currentFrame);
        //cvtColor(currentFrame, currentFrame, COLOR_BGR2GRAY);
        //imshow("GRAY", currentFrame);
    }

    // this line returns 30
    cout << "Frames to process" << framesToProcess.size() << endl;



    // I get runtime error while calling this function  
    getThresholdImage(framesToProcess, thresholdImages);

    //Then I just tried displaying image from captured Mat Vector above with
    //imshow("frame", framesToProcess[0]);
    // Still I get runtime error which means it populates the vector with images but it is not accessible

    // Following section tries to continue with live feed. 
    //Already tried commenting this section but doesn't have any effect
    Image rawImage;
    Error error = camera.RetrieveBuffer(&rawImage);
    if (error != PGRERROR_OK)
    {
        cout << "capture error" << endl;
    }

    // convert to rgb
    Image rgbImage;
    rawImage.Convert(FlyCapture2::PIXEL_FORMAT_BGR, &rgbImage);

    // convert to OpenCV Mat
    unsigned int rowBytes = (double)rgbImage.GetReceivedDataSize() / (double)rgbImage.GetRows();
    cameraFeed = Mat(rgbImage.GetRows(), rgbImage.GetCols(), CV_8UC3, rgbImage.GetData(), rowBytes);
    resize(cameraFeed, cameraFeed, Size(800, 600));

    imshow("camera feed", cameraFeed);
    waitKey(10);
}

}