Opencv CPP program for converting to grey, resizing image and edge detection

#include "opencv\cv.h"
#include "opencv\highgui.h"
#include <iostream>

using namespace cv;
using namespace std;
#define fname "image/b.jpg"

void grey();
int resize(int ht, int wt);
int edge1();
static void onTrackbar(int, void*);

int main(int argc, char** argv)
{
cout<<"Image Location:"<<fname;
IplImage* img = cvLoadImage(fname);
cvNamedWindow( "Example1", CV_WINDOW_AUTOSIZE );
cvShowImage("Example1", img);
cvWaitKey(0);
cvReleaseImage( &img );
cvDestroyWindow( "Example1" );
cout<<"\nGrey conversion..";
grey();
cvWaitKey(0);
cout<<"\n\nEnter pizel size for resize:";
int ht,wt;
cin>>ht;
cin>>wt;
resize(ht,wt);
cvWaitKey(0);
edge1();
cout<<"image saved successfully";
return 0;
}

void grey()
{

    char * file = fname;
    IplImage * img2 = cvLoadImage(file, CV_LOAD_IMAGE_GRAYSCALE);
    cvSaveImage("output/grey.jpg", img2);
    cvNamedWindow( "Grey", CV_WINDOW_AUTOSIZE );
    cvShowImage("Grey", img2);
    cvWaitKey(0);
    cvDestroyWindow("Grey");
    cvReleaseImage(&img2);
}

int resize(int ht, int wt)
{
    IplImage* inputImage = cvLoadImage("output/grey.jpg");
    IplImage* resizedImageLinear =cvCreateImage(cvSize(ht,wt),inputImage->depth, inputImage->nChannels);
    cvResize(inputImage, resizedImageLinear, CV_INTER_LINEAR);
    cvSaveImage("resize/resized.jpg", resizedImageLinear);
    cvNamedWindow("Linear");
    cvShowImage("Linear", resizedImageLinear);
    cvWaitKey(0);
    cvDestroyWindow("Linear");
    cvReleaseImage(&resizedImageLinear);
    return 0;
}

int edgeThresh = 1;
Mat image, gray, edge, cedge;

static void onTrackbar(int, void*)
{
    blur(gray, edge, Size(3,3));
    Canny(edge, edge, edgeThresh, edgeThresh*3, 3);
    cedge = Scalar::all(0);

    image.copyTo(cedge, edge);
    imshow("Edge map", cedge);
    imwrite("edge.jpg",cedge);
}


int edge1()
{
    image = imread(fname, 1);
    if(image.empty())
    {
        printf("Cannot read image file");
        return -1;
    }
    cedge.create(image.size(), image.type());
    cvtColor(image, gray, CV_BGR2GRAY);
    namedWindow("Edge map", 1);
    createTrackbar("Canny threshold", "Edge map", &edgeThresh, 100, onTrackbar);
    onTrackbar(0, 0);
    waitKey(0);
    return 0;
}