How can I get the built in Edge function to work in a dll?

Hello, I'm having a problem using the edge function when I am trying to create a DLL in Matlab. I have created a function that takes in an array (1360,1024, uint16) and performs the Matlab built-in edge function. When I run the function in Matlab I am able to write out the (1360, 1024, logical) and see that there are 0's and 1's in the file. Along with the Original Array.

But when I create a DLL from the same function it will only write out all 0's. But I am able to write out the original array just fine.

I'm a little confused to why this will not work for me. If someone could please help that would be great. Below is the function.

   function edgeThis( a )

    %"a" is a 1360x1024 unit16 array (image from camera)
    %outImg will be the edge detection
    %outImg2 will be the original image from the camera.

        outImg = edge(a,'log',1');
        outName = 'C:\Users\user\Desktop\edgeMe.bin';

    %writes out Edge file in matlab with 0's and 1's but not in DLL
        fid = fopen(outName,'w');
        fwrite(fid,outImg,'uint16');
        fclose(fid);

    %write out original array in both Matlab and DLL

        outName2 = 'C:\Users\user\Desktop\org.bin';
        fid = fopen(outName2,'w');
        fwrite(fid,a,'uint16');
        fclose(fid);

    end

--------------------The C++ code looks like this. ----------------------

#include<iostream>
#include <vector>
#include <conio.h>
#include <ctype.h>
#include <fstream>
#include "edgeThis.h"

    using namespace std;

    int run_main(int argc, char **argv)
    {
      if (!mclInitializeApplication(NULL,0)) 
        {
          std::cerr << "could not initialize the application properly"
                    << std::endl;
            return -1;
        }
    if( !edgeThisInitialize() )
        {
          std::cerr << "could not initialize the library properly"
                    << std::endl;
           return -1;
        }
    try
        {
        int numCol = 1360;
        int numRow = 1024;

                    //create matlab array of size numRow,numCol uint16
                    mwArray inData(numCol, numRow, mxUINT16_CLASS, mxREAL);

                    //declare space for array being read in
                    std::vector <unsigned short> a; 
        band1.resize(numCol*numRow);

                    //file being read in
                    std::string file ("C:\\Users\\user\\Desktop\\dataFile.data");
        ifstream myFile (file, ios::in | ios::binary);

                    //store data from file in variable a
                    myFile.read((char*) &a[0],numCol*numRow*sizeof(short));
                    myFile.close();

                    //set inData to be data from disk read
                    inData.SetData(&a[0], (mwSize)(numRow*numCol));

                    //create edge image and write out using matlab dll 
    //***Again this is where I am having the issue. It will now write out all 0's for the edge file but the original image will be written out just fine through the DLL*****
                    edgeThis(indata); 

     }
      catch (const mwException& e)
        {
          std::cerr << e.what() << std::endl;
          return -2;
        }
      catch (...)
        {
          std::cerr << "Unexpected error thrown" << std::endl;
          return -3;
        }
    edgeThisTerminate();
    mclTerminateApplication();
      return 0;

    int main()
    {
      mclmcrInitialize();

      int ret= mclRunMain((mclMainFcnType)run_main,0,NULL);
      _getch();  //if a characture is hit then window is closed
      return ret;
    }