change the Height and Width of the image

edit

#include "opencv2/opencv.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"

#include <iostream>
#include <stdio.h>

using namespace std;
using namespace cv;

IplImage* doPyrDown(IplImage* in,int filter = IPL_GAUSSIAN_5x5)
{
// Best to make sure input image is divisible by two.
assert( in->width%2 == 0 && in->height%2 == 0 );
IplImage* out = cvCreateImage(cvSize( in->width/2, in->height/2 ),in->depth,in->nChannels);
cvPyrDown( in, out );
return( out );
}

int main( int argc, char* argv[]) 
{
IplImage* img = cvLoadImage( argv[1],1);//load the image and 1 for color image
cvNamedWindow( "Display", CV_WINDOW_AUTOSIZE );//Create and Name the window

doPyrDown(img,0);

cvShowImage( "Display",img);//Display the image
cvWaitKey(0);//wait until user hits a key,if number is +ve then that much milli seconds image will wait to be closed
cvDestroyWindow( "Display" );//Destroy and De-allocate memory
}

hi i got "sample.cpp:15:47: error: ‘IPL_GAUSSIAN_5x5’ was not declared in this scope" while compiling...please help me to get output...