Frames Per Second In OpenCV

Often image processing algorithms are benchmarked using frames per second unit. Frames per second indicate the number of frames processed by the program in a second. Here is a short listing for finding the frames per second

#include<highgui.h>
#include<cv.h>
#include<time.h>
#include<stdio.h>
#define h 280
#define w 320
using namespace std;

int main()
{
//Start and end times
time_t start,end;
//Stucture to get feed from cam
CvCapture* cap=cvCreateCameraCapture(0);
//Windows
cvNamedWindow("Cam Feed",CV_WINDOW_AUTOSIZE);

//Start the clock
time(&start);
int counter=0;

while(1)
{
//Getting the present frame
IplImage* fram=cvQueryFrame(cap);
if(!fram)
printf("\nPlease check your webcam connection");
//Showing the frame
cvShowImage("Cam Feed",fram);
//Stop the clock and show FPS
time(&end);
++counter;
double sec=difftime(end,start);
double fps=counter/sec;
printf("\n%lf",fps);
//Escape Sequence
char c=cvWaitKey(33);
if(c==27)
break;

}
//Cleanup
cvReleaseCapture(&cap);
cvDestroyAllWindows();

}

Here is the output

To find the FPS of video replace  cvCreateCameraCapture with        cvCreateFileCapture(“Filename”);