从摄像头批量截取图片

// hand gesture sampler.cpp : Defines the entry point for the console application.

//
#include "stdafx.h"
#include <string>
#include <iostream>

#include <opencv2\opencv.hpp>

using namespace cv;
using namespace std;

Mat src, src2Save;
char cfileName[1024];
string sfileName = "";
Size outputSize = Size(320, 240);

template <typename T> string NumberToString ( T Number );
void help();


int main()
{
    help();

    namedWindow("monitor", 1);

    VideoCapture cap(0);

    if(cap.isOpened())
    {
        int c = 0;
        int num = 0;
        bool sampleState = false;

        //main loop
        while( c != 27)
        {
            if(c == 98) sampleState = true;
            if(c == 115) sampleState = false;

            //get webcam image
            cap >> src;

            //resize image to 320*240
            if(src.cols > 320 || src.rows > 240) resize(src, src2Save, outputSize, 0.5, 0.5, 1);

            //show image
            imshow("monitor", src2Save);

            //save image            
            sfileName = "f:/documents/Downloads/hand gesture pictures/" + NumberToString(num) + ".png";
            if(sampleState) 
            { 
                imwrite(sfileName, src2Save); 
                num ++;
                cout<<"\nCollected Sample Number - " << num << endl;
            }            

            //exit loop
            c = waitKey(10);
        }
    }
    else
        //end app
        return -1;

    return 0;
}

template <typename T>
  string NumberToString ( T Number )
  {
     ostringstream ss;
     ss << Number;
     return ss.str();
  }

void help()
{
    printf(
        "========================\n"
        "========================\n"
        "Programme to collect a good number of hand gestures from video streams.\n"
        "Usage:\n"
        "(s)top - stop sampling\n"
        "(b)egin - begin sampling\n"
        "ESC - exit the programme\n"
        "==========================\n"
        "==========================\n"
        );
}