单高斯背景建模

不念不忘少年蓝@ 2022-10-15 10:57 133阅读 0赞

# 算法原理 #

![Center][]

![Center 1][]

![Center 2][]

# Opencv实现 #

/*******************单高斯背景建模v1.0*************************
    ************************2010.01.22****************************/
    
    #include <highgui.h>
    #include <cv.h>
    #include <math.h>
    #include <stdio.h>
    #include <stdlib.h>
    
    int main(int argc, char **argv)
    {
        //新建窗口
        cvNamedWindow("origin", CV_WINDOW_AUTOSIZE);
        cvNamedWindow("processing", CV_WINDOW_AUTOSIZE);
    
        double alpha = 0.05;    //背景建模alpha值
        double std_init = 20;    //初始标准差
        double var_init = std_init * std_init;    //初始方差    
        double lamda = 2.5 * 1.2;    //背景更新参数
    	
    	char* fileName="E:\\研二上\\video\\highway.AVI";
    
        //视频文件
        CvCapture *capture = NULL;
    
    //     //读取视频文件
    //     if (argc == 1)
    //     {
    //         //从摄像头读入
    //         capture = cvCreateCameraCapture(0);
    //     }
    //     else if (argc == 2)
    //     {
    //         //从文件读入
    //         capture = cvCreateFileCapture(argv[1]);
    //     }
    //     else
    //     {
    //         //读入错误
    //         printf("input error\n");
    //         return -1;
    //     }
    
    	capture = cvCreateFileCapture(fileName);
    
    
        IplImage *frame = NULL;        //原始图像
        IplImage *frame_u = NULL;    //期望图像
        IplImage *frame_var = NULL;    //方差图像
        IplImage *frame_std = NULL;    //标准差
    
        CvScalar pixel = {0};        //像素原始值
        CvScalar pixel_u = {0};        //像素期望
        CvScalar pixel_var = {0};    //像素方差
        CvScalar pixel_std = {0};    //像素标准差
    
        //初始化frame_u, frame_var, frame_std
        frame = cvQueryFrame(capture);
        frame_u = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3);
        frame_var = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3);
        frame_std = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3);
    
        for (int y = 0; y < frame->height; ++y)
        {
            for (int x = 0; x < frame->width; ++x)
            {
                pixel = cvGet2D(frame, y, x);
    
                pixel_u.val[0] = pixel.val[0];
                pixel_u.val[1] = pixel.val[1];
                pixel_u.val[2] = pixel.val[2];
    
                pixel_std.val[0] = std_init;
                pixel_std.val[1] = std_init;
                pixel_std.val[2] = std_init;
    
                pixel_var.val[0] = var_init;
                pixel_var.val[1] = var_init;
                pixel_var.val[2] = var_init;
    
                cvSet2D(frame_u, y, x, pixel_u);
                cvSet2D(frame_var, y, x, pixel_var);
                cvSet2D(frame_std, y, x, pixel_std);
            }
        }
    
        while (cvWaitKey(33) != 27)        //按ESC键退出, 帧率33ms
        {
            frame = cvQueryFrame(capture);
    
            //视频结束退出
            if (!frame)
            {
                break;
            }
    
            //单高斯背景更新
            for (int y = 0; y < frame->height; ++y)
            {
                for (int x = 0; x < frame->width; ++x)
                {
                    pixel = cvGet2D(frame, y, x);
                    pixel_u = cvGet2D(frame_u, y, x);
                    pixel_std = cvGet2D(frame_std, y, x);
                    pixel_var = cvGet2D(frame_var, y, x);
    
                    //|I-u| < lamda*std 时认为是背景, 进行更新
                    if (fabs(pixel.val[0] - pixel_u.val[0]) < lamda * pixel_std.val[0] &&
                        fabs(pixel.val[1] - pixel_u.val[1]) < lamda * pixel_std.val[1] &&
                        fabs(pixel.val[2] - pixel_u.val[2]) < lamda * pixel_std.val[2])
                    {
                        //更新期望 u = (1-alpha)*u + alpha*I
                        pixel_u.val[0] = (1 - alpha) * pixel_u.val[0] + alpha * pixel.val[0];
                        pixel_u.val[1] = (1 - alpha) * pixel_u.val[1] + alpha * pixel.val[1];
                        pixel_u.val[2] = (1 - alpha) * pixel_u.val[2] + alpha * pixel.val[2];
    
                        //更新方差 var = (1-alpha)*var + alpha*(I-u)^2
                        pixel_var.val[0] = (1 - alpha) * pixel_var.val[0] +
                                        (pixel.val[0] - pixel_u.val[0]) * (pixel.val[0] - pixel_u.val[0]);
                        pixel_var.val[1] = (1 - alpha) * pixel_var.val[1] +
                                        (pixel.val[1] - pixel_u.val[1]) * (pixel.val[1] - pixel_u.val[1]);
                        pixel_var.val[2] = (1 - alpha) * pixel_var.val[2] +
                                        (pixel.val[2] - pixel_u.val[2]) * (pixel.val[2] - pixel_u.val[2]);
    
                        //更新标准差
                        pixel_std.val[0] = sqrt(pixel_var.val[0]);
                        pixel_std.val[1] = sqrt(pixel_var.val[1]);
                        pixel_std.val[2] = sqrt(pixel_var.val[2]);
    
                        //写入矩阵
                        cvSet2D(frame_u, y, x, pixel_u);
                        cvSet2D(frame_var, y, x, pixel_var);
                        cvSet2D(frame_std, y, x, pixel_std);
                    }
                }
            }
    
            //显示结果
            cvShowImage("origin", frame);
            cvShowImage("processing", frame_u);
        }
    
        //释放内存
        cvReleaseCapture(&capture);
        cvReleaseImage(&frame);
        cvReleaseImage(&frame_u);
        cvReleaseImage(&frame_var);
        cvReleaseImage(&frame_std);
        cvDestroyWindow("origin");
        cvDestroyWindow("processing");
    
        return 0;
    }

# matlab实现 #

close all;
    clear all;
    
    mov=aviread('E:\研二上\video\highway.AVI'); %读入
    fnum=size(mov,2); %读取电影的祯数，mov为1*temp
    
    alpah=0.005;
    std_init=20;
    var_init=std_init*std_init;
    lamda=2.5*2.5;
    
    frame=uint8(ones(304,400,3));
    frame_u=frame;
    frame_var=frame;
    frame_std=frame;
    
    
    % frame=imread('D:\Code\Data\00011\1.bmp');
    frame=mov(1).cdata(:,:,:);
    frame_u=frame;
    frame_var=var_init*frame_var;
    frame_std=std_init*frame_std;
    
    
    for index=2:fnum
    %     fileName=strcat('D:\Code\Data\00011\',int2str(index),'.','bmp'); %将每祯转成jpg的图片
    %     frame=imread(fileName);
        frame=mov(index).cdata(:,:,:);
        [x,y,z]=size(frame);
        for i=1:x
            for j=1:y
                frame_rgb=frame(i,j,:);
                frame_u_rgb=frame_u(i,j,:);
                frame_std_rgb=frame_std(i,j,:);
                frame_var_rgb=frame_var(i,j,:);
                if company_rgb(frame_rgb,frame_u_rgb,lamda,frame_std_rgb)
                       frame_u_rgb=(1-alpah).*frame_u_rgb+alpah.*frame_var_rgb;
                       frame_var_rgb=(1-alpah).*frame_var_rgb+alpah.*(frame_rgb-frame_u_rgb).^2;
                                   
                       frame_std_rgb=sqrt(double(frame_var_rgb));
                
                       frame_u(i,j,:)= frame_u_rgb;
                       frame_std(i,j,:)=frame_std_rgb;
                       frame_var(i,j,:)=frame_var_rgb;
                       
                end
            end
        end
       
        subplot(2,1,1);
        imshow(frame);
        title('src');
        subplot(2,1,2);
        imshow(frame_u);
        title('result');
        
        pause(0.01);
    end

function [ output_args ] = company_rgb( frame_rgb,frame_u_rgb,lamda,frame_std_rgb )
    %UNTITLED2 Summary of this function goes here
    %   Detailed explanation goes here
        var_r=abs(frame_rgb(1)-frame_u_rgb(1));
        var_g=abs(frame_rgb(2)-frame_u_rgb(2));
        var_b=abs(frame_rgb(3)-frame_u_rgb(3));
        if var_r<lamda*frame_std_rgb(1) && var_g<lamda*frame_std_rgb(2) && var_b<lamda*frame_std_rgb(3)
            output_args=1;
        else
            output_args=0;
        end
    end

[Center]: /images/20221014/0f4e532df9914889ad820282fe83db68.png
[Center 1]: /images/20221014/3e10780fc8534b429879fd0f024f7183.png
[Center 2]: /images/20221014/603ccb68fb3348758d43ce6cd2b86c17.png