Question

我有检测脸部的代码..如何保存正在捕获的视频？我在下面发布了面部检测代码。我在哪里插入保存视频的代码？这段代码用于检测ubuntu和opencv的面部。请帮忙！

 #include <opencv2/objdetect/objdetect.hpp>
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/imgproc/imgproc.hpp>

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

 using namespace std;
 using namespace cv;


           VideoCapture cap;
           cv::VideoWriter output_cap("/home/unifyadmin/Documents/MyVideo.avi", 
           input_cap.get(CV_CAP_PROP_FOURCC),
           input_cap.get(CV_CAP_PROP_FPS),
           cv::Size(input_cap.get(CV_CAP_PROP_FRAME_WIDTH),
           input_cap.get(CV_CAP_PROP_FRAME_HEIGHT)));

       if (!output_cap.isOpened())
     {
    std::cout << "!!! Output video could not be opened" << std::endl;
    return;
           }

                // This part would be similar to your imshow part of your code
           while (true)
          {       
         if (!input_cap.read(frame))             
          break;

            output_cap.write(frame);
         }

 /** Function Headers */
 void detectAndDisplay( Mat frame );

 /** Global variables */
 String face_cascade_name = "haarcascade_frontalface_alt.xml";
 String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
 CascadeClassifier face_cascade;
 CascadeClassifier eyes_cascade;
 string window_name = "Capture - Face detection";
 RNG rng(12345);

 /** @function main */
 int main( int argc, const char** argv )
 {
   CvCapture* capture;
   Mat frame;

   //-- 1. Load the cascades
   if( !face_cascade.load( face_cascade_name ) ){ printf("--(!)Error loading\n"); return -1; };
   if( !eyes_cascade.load( eyes_cascade_name ) ){ printf("--(!)Error loading\n"); return -1; };

   //-- 2. Read the video stream
   capture = cvCaptureFromCAM( 0 );
   if( capture )
   {
     while( true )
     {
   frame = cvQueryFrame( capture );

   //-- 3. Apply the classifier to the frame
       if( !frame.empty() )
       { detectAndDisplay( frame ); }
       else
       { printf(" --(!) No captured frame -- Break!"); break; }

       int c = waitKey(10);
       if( (char)c == 'c' ) { break; }
      }
   }
   return 0;
 }

/** @function detectAndDisplay */
void detectAndDisplay( Mat frame )
{
  std::vector<Rect> faces;
  Mat frame_gray;

  cvtColor( frame, frame_gray, CV_BGR2GRAY );
  equalizeHist( frame_gray, frame_gray );

  //-- Detect faces
  face_cascade.detectMultiScale( frame_gray, faces, 1.1, 2, 0|CV_HAAR_SCALE_IMAGE, Size(30, 30) );

  for( size_t i = 0; i < faces.size(); i++ )
  {
    Point center( faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5 );
    ellipse( frame, center, Size( faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar( 255, 0, 255 ), 4, 8, 0 );

    Mat faceROI = frame_gray( faces[i] );
    std::vector<Rect> eyes;

    //-- In each face, detect eyes
    eyes_cascade.detectMultiScale( faceROI, eyes, 1.1, 2, 0 |CV_HAAR_SCALE_IMAGE, Size(30, 30) );

    for( size_t j = 0; j < eyes.size(); j++ )
     {
       Point center( faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5 );
       int radius = cvRound( (eyes[j].width + eyes[j].height)*0.25 );
       circle( frame, center, radius, Scalar( 255, 0, 0 ), 4, 8, 0 );
     }
  }
  //-- Show what you got
  imshow( window_name, frame );
 }

Answer 1

您需要三个library method：

VideoWriter::VideoWriter(const string& filename, int fourcc, double fps, Size frameSize, bool isColor=true)
VideoWriter::open(const string& filename, int fourcc, double fps, Size frameSize, bool isColor=true)
void VideoWriter::write(const Mat& image)

以下是如何使用它们的简短示例：

// Do this near the start of your code
cv::VideoWriter output_cap(C:/MyVideo.avi, 
               input_cap.get(CV_CAP_PROP_FOURCC),
               input_cap.get(CV_CAP_PROP_FPS),
               cv::Size(input_cap.get(CV_CAP_PROP_FRAME_WIDTH),
               input_cap.get(CV_CAP_PROP_FRAME_HEIGHT)));

    if (!output_cap.isOpened())
{
        std::cout << "!!! Output video could not be opened" << std::endl;
        return;
}

// This part would be similar to your imshow part of your code
while (true)
{       
    if (!input_cap.read(frame))             
        break;

    output_cap.write(frame);
}

编辑： - 我对这个问题的最后贡献：

您需要在main函数中创建对象，包括VideoWriter

我不确定这些代码是如何工作的：

       VideoCapture cap;
       cv::VideoWriter output_cap("/home/unifyadmin/Documents/MyVideo.avi", 
       input_cap.get(CV_CAP_PROP_FOURCC),
       input_cap.get(CV_CAP_PROP_FPS),
       cv::Size(input_cap.get(CV_CAP_PROP_FRAME_WIDTH),
       input_cap.get(CV_CAP_PROP_FRAME_HEIGHT)));

   if (!output_cap.isOpened())
 {
std::cout << "!!! Output video could not be opened" << std::endl;
return;
       }

            // This part would be similar to your imshow part of your code
       while (true)
      {       
     if (!input_cap.read(frame))             
      break;

        output_cap.write(frame);
     }

您需要考虑您实际编码的内容以及编写代码的位置。不要只是从互联网上拿例子，试着把它们粘在一起。

opencv-face detection - 保存视频

1 个答案: