[opencv入门笔记] 读视频转图像—读取视频中每一帧图像

#include <opencv2 core="" core="" hpp="">#include <opencv2 highgui="" highgui="" hpp="">#include <opencv2 imgproc="" imgproc="" hpp="">#include <iostream>using namespace std;using namespace cv;int main(){//打开视频文件：其实就是建立一个VideoCapture结构  VideoCapture capture("F:\\6.avi");//检测是否正常打开:成功打开时，isOpened返回ture  if (!capture.isOpened())cout << "fail toopen!" << endl;//获取整个帧数  long totalFrameNumber = capture.get(CV_CAP_PROP_FRAME_COUNT);cout << "整个视频共" << totalFrameNumber << "帧" << endl;//设置开始帧()  long frameToStart = 1;capture.set(CV_CAP_PROP_POS_FRAMES, frameToStart);cout << "从第" << frameToStart << "帧开始读" << endl;//设置结束帧  int frameToStop = 30;if (frameToStop< frameToStart){cout << "结束帧小于开始帧，程序错误，即将退出！" << endl;return - 1;}else {cout << "结束帧为：第" << frameToStop << "帧" << endl;}//获取帧率  double rate = capture.get(CV_CAP_PROP_FPS);cout << "帧率为:" << rate << endl;//定义一个用来控制读取视频循环结束的变量  bool stop = false;//承载每一帧的图像  Mat frame;//显示每一帧的窗口  namedWindow("Extractedframe");//两帧间的间隔时间:  //int delay = 1000/rate;  double delay = 1000 / rate;//利用while循环读取帧  //currentFrame是在循环体中控制读取到指定的帧后循环结束的变量  long currentFrame = frameToStart;//滤波器的核  int kernel_size = 3;Mat kernel = Mat::ones(kernel_size, kernel_size, CV_32F) / (float)(kernel_size*kernel_size);while (!stop){//读取下一帧  if (!capture.read(frame)){cout << "读取视频失败" << endl;return - 1;}cout << "正在读取第" << currentFrame << "帧" << endl;imshow("Extractedframe", frame);cout << "正在写第" << currentFrame << "帧" << endl;stringstream str;str << "sample" << currentFrame << ".png";cout << str.str() << endl;imwrite(str.str(), frame);//waitKey(intdelay=0)当delay≤ 0时会永远等待；当delay>0时会等待delay毫秒  //当时间结束前没有按键按下时，返回值为-1；否则返回按键  int c = waitKey(delay);//按下ESC或者到达指定的结束帧后退出读取视频  if ((char)c == 27 || currentFrame > frameToStop){stop = true;}//按下按键后会停留在当前帧，等待下一次按键  if (c >= 0){waitKey(0);}currentFrame++;}//关闭视频文件  capture.release();waitKey(0);return 0;}</iostream></opencv2></opencv2></opencv2>

开始帧1， 结束帧30 ，得到的结果如下  ：