一段机械的平均图像求背景的代码

#include<opencv2/opencv.hpp>
#include<iostream>
#include<Eigen/Dense>
#include<string>
cv::Mat getAverageBG(cv::VideoCapture& capture,int start,int end){
    long frameCount = end - start;
    int index = 0;
    int width = capture.get(CV_CAP_PROP_FRAME_WIDTH);
    int height = capture.get(CV_CAP_PROP_FRAME_HEIGHT);

    Eigen::MatrixXd averageBgR(height, width);
    Eigen::MatrixXd averageBgG(height, width);
    Eigen::MatrixXd averageBgB(height, width);
    for (int i = 0; i < height; i++){
        for (int j = 0; j < width; j++){
            averageBgR(i, j) = 0;
            averageBgG(i, j) = 0;
            averageBgB(i, j) = 0;
        }
    }

    for (int i = start; i < end; i++){
        index++;
        //移动内部指针到视频图像的第i帧
        capture.set(CV_CAP_PROP_POS_FRAMES, i);
        cv::Mat curMat;
        capture.read(curMat);
        for (int i = 0; i < height; i++){
            cv::Vec3b* p = curMat.ptr<cv::Vec3b>(i);
            for (int j = 0; j < width; j++){
                averageBgR(i, j) += p[j][0] ;
                averageBgG(i, j) += p[j][1] ;
                averageBgB(i, j) += p[j][2] ;
            }
        }
        std::cout << index<<"/"<<frameCount << std::endl;
    }//for every frame

    cv::Mat result(height,width,CV_8UC3);
    for (int i = 0; i < height; i++){
        for (int j = 0; j < width; j++){
            cv::Vec3b p;
            //std::cout << averageBgR(i, j) << std::endl;
            p[0] = static_cast<uchar>(averageBgR(i, j) / (float)frameCount);
            p[1] = static_cast<uchar>(averageBgG(i, j) / (float)frameCount);
            p[2] = static_cast<uchar>(averageBgB(i, j) / (float)frameCount);
            result.at<cv::Vec3b>(i, j) = p;
        }
    }
    return result;
}
int main(int argc,char* argv[]){
    cv::VideoCapture capture;
    if (argc < 3){
        return 1;
    }
    std::string fileName(argv[1]);
    std::string outName(argv[2]);

    if (!capture.open(fileName)){
        std::cout << "can not open video" << std::endl;
        return 1;
    }
    
    long frameCount = static_cast<long>(capture.get(CV_CAP_PROP_FRAME_COUNT));
    cv::Mat bg = getAverageBG(capture, 0, frameCount);
    
    cv::imwrite(outName, bg);
    cv::imshow("", bg);
    cv::waitKey();
    return 0;
}