Question

我想显示视频文件中每个帧的更新直方图

捕获视频文件，然后传递给直方图计算功能

我对以下代码进行了一些更改。但它没有按我的意愿工作。

我感谢任何帮助

此致

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "iostream"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>

using namespace cv;
using namespace std;

 void histogramcalculation(const Mat &Image, Mat &histoImage)
{  
 int histSize = 255;
 // Set the ranges ( for B,G,R) )

float range[] = { 0, 256 } ;
const float* histRange = { range };
bool uniform = true; bool accumulate = false;
Mat b_hist, g_hist, r_hist;


 // Compute the histograms:

calcHist( &Image, 1, 0, Mat(), b_hist, 1, &histSize,  &histRange,    uniform, accumulate );


// Draw the histogram

  int hist_w = 512; int hist_h = 400;
  int bin_w = cvRound( (double) hist_w/histSize );
  Mat histImage( hist_h, hist_w, CV_8UC3, Scalar( 0,0,0) );

// Normalize the result to [ 0, histImage.rows ]

normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());


   // Draw 

  for( int i = 1; i < histSize; i++ )

 {
 line( histImage, Point( bin_w*(i-1), hist_h - cvRound(b_hist.at<float>   (i-1)) ) , Point( bin_w*(i), hist_h - cvRound(b_hist.at<float>(i)) ),   Scalar( 255, 0, 0), 2, 8, 0 );



  }
 histoImage= histImage;

 }

int main( )
 {

 Mat histImage;

VideoCapture cap("eye.mp4"); // open video
if(!cap.isOpened())  // check if we succeeded
    return -1;

 namedWindow("Video",1);
 namedWindow("ycbcr",1);
 while(1)
 {
    Mat frame;

    cap >> frame; // get a new frame

   imshow( "video", frame );

// Calculate the histogram

 histogramcalculation(frame, histImage);

// Display the histogram 

 imshow("Colour Image Histogram", histImage );

 // Wait until user exits the program

 waitKey();

  }
return 0;
}

Answer 1

以下代码将为grayScale图像绘制直方图。如果要绘制彩色图像的直方图，则必须将图像分割为单独的通道，并且这些单独的通道可以单独绘制直方图。

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "iostream"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>

using namespace cv;
using namespace std;

 void histogramcalculation(const Mat &Image, Mat &histoImage)
{  
 int histSize = 255;
 // Set the ranges ( for B,G,R) )

float range[] = { 0, 256 } ;
const float* histRange = { range };
bool uniform = true; bool accumulate = false;
Mat b_hist, g_hist, r_hist;


 // Compute the histograms:

calcHist( &Image, 1, 0, Mat(), b_hist, 1, &histSize,  &histRange,    uniform, accumulate );


// Draw the histogram

  int hist_w = 512; int hist_h = 400;
  int bin_w = cvRound( (double) hist_w/histSize );
  Mat histImage( hist_h, hist_w, CV_8UC3, Scalar( 0,0,0) );

// Normalize the result to [ 0, histImage.rows ]

normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat());


   // Draw 

  for( int i = 1; i < histSize; i++ )

 {
 line( histImage, Point( bin_w*(i-1), hist_h - cvRound(b_hist.at<float>   (i-1)) ) , Point( bin_w*(i), hist_h - cvRound(b_hist.at<float>(i)) ),   Scalar( 255, 0, 0), 2, 8, 0 );



  }
 histoImage= histImage;

 }

int main( )
 {

 Mat histImage;

VideoCapture cap("test1.avi"); // open video
if(!cap.isOpened())  // check if we succeeded
    return -1;

 while(1)
 {
    Mat frame;

    cap >> frame; // get a new frame


   imshow( "video", frame );
   cvtColor(frame, frame, CV_BGR2GRAY );

// Calculate the histogram

 histogramcalculation(frame, histImage);

// Display the histogram 

 imshow("Gray Scale Image Histogram", histImage );

 // Wait until user exits the program

 waitKey(5);

  }
return 0;
}

显示每个框架的更新视频直方图

1 个答案: