Question

我正致力于立体视觉。我有两个立体视频。我想做以下事情

1]从视频中提取第一帧。

2]将帧转换为灰色通道（以便我可以应用SURF功能）

3]显示第一帧（在下面给出的代码中得到错误）

4]存储小尺寸的视频（目前为1600 * 1200）

任何人都可以提出建议怎么办？我的代码如下（用c ++编写）

 #include <stdio.h>
 #include <iostream>
 #include <vector>
 #include <time.h>
 #include <opencv2\core\core.hpp>
 #include <opencv2\highgui\highgui.hpp>
 #include <opencv2\imgproc\imgproc.hpp>
 #include "opencv2\features2d\features2d.hpp"
 #include "opencv2\nonfree\features2d.hpp"
 #include "opencv2\nonfree\nonfree.hpp"
 #include "opencv2\flann\flann.hpp"
 #include "opencv2\contrib\contrib.hpp"
 #include <opencv2\calib3d\calib3d.hpp>
 #include <opencv2\gpu\gpumat.hpp>
 #pragma comment (lib, "opencv_core243d")
 #pragma comment (lib, "opencv_highgui243d")
 #pragma comment (lib, "opencv_imgproc243d")
 #pragma comment (lib, "opencv_features2d243d")
 #pragma comment (lib, "opencv_nonfree243d")
 #pragma comment (lib, "opencv_flann243d")
 #pragma comment (lib, "opencv_contrib243d")
 #pragma comment (lib, "opencv_calib3d243d")
 #pragma comment (lib, "opencv_gpu243d")
 using namespace std;
 using namespace cv;

     int main(int argc, char**argv)
      {
     clock_t start_time=clock();
     long lframecount=0;
      //load the videos
     VideoCapture capture1(argv[1]); 
    VideoCapture capture2(argv[2]);
     cout << argv[1]  << endl;
     cout << argv[2]  << endl;

     if(!capture1.isOpened()||!capture2.isOpened())
     {
       cout<<"cant load stereo video";
         return -1;
       }

      Mat frame1,frame2;
      capture1>>frame1;
      capture2>>frame2;
       int num_rows=frame1.rows;
       int num_cols=frame1.cols;
       std::cout<<"number of rows and colums"<<num_rows<<":"<<num_cols<<std::endl;
       int output_rows=num_rows/4;
       int output_cols=num_cols/4;
       long framecount1= capture1.get(CV_CAP_PROP_FRAME_COUNT);
       long framecount2= capture2.get(CV_CAP_PROP_FRAME_COUNT);

       VideoWriter write;
    write.open("E:\\Vipil\\open_cv_learning\\video\\new22.avi",CV_FOURCC('D','I','V','X'), 30,cv::Size(output_rows,output_cols) ,true);
     if (!write.isOpened())
     {
        std::cout << "cant open output video";
         return -1;
     }
     namedWindow("depthmap",cv::WINDOW_NORMAL);
     cv::Point tex(570, 50);
      cv::Mat image1;
      cv::Mat image2;
     for(long i=1;i<6;i++)
    {

        lframecount++;
        int number=lframecount;
        string frame;
         std::ostringstream convert;
         convert<<number;
        frame = convert.str();
        capture1>> frame1;
            capture2>> frame2;
         cv::cvtColor(frame1,image1,CV_RGB2GRAY);
         cv::cvtColor(frame2,image2,CV_RGB2GRAY);
        imshow("image1",frame1);
       //cout<<lframecount<<"\n";
}

Answer 1

您需要使用waitKey（30）或一些延迟才能正确显示图像。另外，要调整框架大小，您只需使用OpenCV resize（）函数即可。这是参考 http://docs.opencv.org/modules/imgproc/doc/geometric_transformations.html

使用open cv显示视频中的第一帧？

1 个答案: