Floating point exception when looping and reading images

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I'm building a line following robot with OpenCV (c++), Raspberry Pi, Arduino, and an Arducam. I keep getting a Floating point exception when I decrease the delay time between image scans (at the end of the loop in main(), down to a 1 second delay). A bash script simultaneously captures an image from the Arducam, and the c++ program continuously reads the same image file name that's being written over.

At first I thought the exception was thrown because the image file was not finished being written to before it was read, but I wrote the loadImage() method in a way where (I hope) the method would not return until the data is complete. It could be wrong, I am just looking for a way to avoid or ignore the Floating point exception.

#include <iostream>
#include <string>
#include <opencv2/opencv.hpp>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/i2c-dev.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <iostream>

#define ADDRESS 0x04                        // The Arduino I2C address
static const char *devName = "/dev/i2c-1";  // The I2C bus

using namespace cv;
using namespace std;

// Line Detection program

// Efficient method to reduce noise
Mat& scanAndReduce(Mat& I, const int* const table)
{
    // accept only char type matrices
    CV_Assert(I.depth() == CV_8U);
    int channels = I.channels();
    int nRows = I.rows;
    int nCols = I.cols * channels;
    if (I.isContinuous())
    {
        nCols *= nRows;
        nRows = 1;
    }
    int i,j;
    uchar* p;
    for( i = 0; i < nRows; ++i)
    {
        p = I.ptr<uchar>(i);
        for ( j = 0; j < nCols; ++j)
        {
            p[j] = table[p[j]];
        }
    }
    return I;
}

// Loads command-line argument image file location
int loadImage(Mat& source, char argv[])
{ 
    while ( !source.data )
    {
        source = imread(argv, 0);
    }
    return 0;
}

// Displays input image in new window
void display(Mat& image)
{
    namedWindow("Result", WINDOW_NORMAL);
    imshow("Result", image);
    waitKey(0);
}
// prints 10x10 ellipse with input center and height to input matrix
void drawEllipse(Mat& destination, int center, int lineY)
{
    ellipse( destination,                       // destination matrix
            Point(center,lineY),                // location
            Size(20,20),                        // size
            0,                                  // angle
            0,                                  // start
            360,                                // end
            Scalar(100,0,0));                   // color
}
// Scan bottom half of screen to see where line is
int scanLines(Mat& sourceImage)
{
    int diff = (sourceImage.rows) * 0.1;        // distance between scan lines
    int lineY = (sourceImage.rows) * 0.9;       // starting scan line
    int vals[sourceImage.cols];                 // save line values (left to right)
    int center = 0;                             // sums indexes of dark values
    int numDark = 0;                            // tracks dark values
    int offset = 0;

    // get values along scan lines
    for(int i = 0; i < 5; i++)                  // traverse y axis (bottom to top)
    {
        center = 0;                             // sums indexes of dark values
        numDark = 0;                            // tracks dark values
        Scalar intensity;
        int leftBound = sourceImage.cols * 0.25;
        int rightBound = sourceImage.cols * 0.75;
        for(int j = leftBound; j < rightBound; j++) // traverse x axis of image
        {
            intensity = sourceImage.at<uchar>(Point(j,lineY)); // save value
            vals[j] = intensity[0];             // get first value (greyscale)
            // save dark value
            if(vals[j] < 100)
            {
                center += j;                    // add index to sum
                numDark++;                      // increment dark ...