Loading an Image in OpenCV

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include<opencv2\opencv.hpp>
#include <opencv2\highgui\highgui.hpp>



int main(int argc, char *argv[])
{
IplImage* img = 0;
int height,width,step,channels;
uchar *data;
int i,j,k;
char* change_im(char*);
char *im = "";


if(argc<2){
printf("Usage: main <image-file-name>\n\7");
im = "aresh.jpg"; //decalre DEFAULT
}
else
{
im = argv[1];
}


// load an image
img=cvLoadImage(im);
if(!img){
printf("Could not load image file: %s\n",im);
exit(0);
}



// get the image data
height = img->height;
width = img->width;
step = img->widthStep;
channels = img->nChannels;
data = (uchar *)img->imageData;
printf("Processing a %dx%d image with %d channels\n",height,width,channels);



// create a window
cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
cvMoveWindow("mainWin", 100, 100);



// show the image
cvShowImage("mainWin", img );



// wait for a key
cvWaitKey(0);



// release the image
cvReleaseImage(&img );
return 0;
}