I hope this helps :)
#include <stdio.h>
#include "cv.h"
#include "highgui.h" int main() {
IplImage *img=NULL; //pull picture in //for reading image
img=cvLoadImage("test.jpg"); //image path, put in the proj folder
IplImage *smallImage=cvCreateImage(cvSize(50,50),img->depth,img->nChannels);
IplImage *largeImage=cvCreateImage(cvSize(256,256),img->depth,img->nChannels);
cvShowImage("Test",img);// put it on top
cvResize(img,smallImage);
cvResize(img,largeImage);
cvShowImage("Large",largeImage);
cvShowImage("Small",smallImage); cvWaitKey(0); cvReleaseImage(&img); return 0; }