均值背景建模

Bertha 。 2023-01-22 11:47 159阅读 0赞

# 算法原理 #

原理， ![20130915104534500][]，将所有帧的像素点相加，取平均作为背景的估计，其中N是当前所在帧，不是所有帧。

# Matlab实现 #

mov=aviread('highway.AVI');      %读入
    fnum=size(mov,2)               ; %读取电影的祯数，mov为1*temp
    [x,y,z]=size(mov(1).cdata(:,:,:));
    frame_src=zeros(x,y,z);       %原始图像
    frame_all=zeros(x,y,z);  
    frame_avg=zeros(x,y,z);       %平均图像
    frame_src_avg=zeros(x,y,z);   %原始图像减平均图像
    frame_src_avg_all=zeros(x,y,z); 
    frame_result=zeros(x,y,z);
    for i=1:fnum
        frame_src=mov(i).cdata(:,:,:);
        frame_src=double(frame_src);
        frame_all=frame_all+frame_src;
        frame_avg=frame_all/i;
    %     frame_src_avg=sqrt(frame_src.^2-frame_avg.^2);
    %     frame_src_avg_all=frame_src_avg_all+frame_src_avg;
    %     frame_result=frame_src_avg/i;
        subplot(2,2,1);
        frame_src=uint8(frame_src);
        imshow(frame_src);
        title('原始图像');
        subplot(2,2,2);
        frame_avg=uint8(frame_avg);
        imshow(frame_avg);
        title('背景');
        
    %     frame_src_gray=rgb2gray(frame_src);
    %     frame_avg_gray=rgb2gray(frame_avg);
    %     f=frame_src_gray-frame_avg_gray;
    %     subplot(2,2,3);
    %     imshow(f);
        pause(0.1);
    end

# 实现效果 #

![Image 1][]

![Center][]

# Opencv实现 #

#include "cv.h"
    #include "cxcore.h"
    #include "highgui.h"
    #include <stdio.h>
    #include<math.h>
    
    #define image_width 320
    #define image_height 240
    
    int main(int argc,char** argv)
    {
    	int i;
    	double alpha=0.0,beta=0.0;
    	CvCapture* capture=cvCaptureFromAVI("E:\\研二上\\video\\highway.AVI");
    	if(!capture)
    	{
    		printf("Could not initialize...\n");
    		return -1;
    	}
    	IplImage* img=cvQueryFrame(capture);
    	IplImage* background=cvCreateImage(cvSize(img->width,img->height),img->depth,3);
    	IplImage* advbackground=cvCreateImage(cvSize(img->width,img->height),img->depth,3);
    	int index=0;
    
    	cvNamedWindow("video",1);
    	cvNamedWindow("back",1);
    	cvNamedWindow("advback",1);
    
    	CvMat* Mat_src=cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat_dst=cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat_dst1=cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat_tmp1=cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat_tmp2=cvCreateMat(img->height,img->width,CV_32FC3);
    
    	CvMat* Mat1 = cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat2 = cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat3 = cvCreateMat(img->height,img->width,CV_32FC3);
    	CvMat* Mat4 = cvCreateMat(img->height,img->width,CV_32FC3);
    	cvSetZero(Mat_dst);
    	cvSetZero(Mat2);
    	cvSetZero(Mat3);
    
    	while(img=cvQueryFrame(capture)) 
    	{
    		index++;
    		printf("index%d\n",index);
    		cvShowImage("video",img);
    		cvConvert(img,Mat_src);                                    //转换成32位浮点型		
    			cvAdd(Mat_src,Mat_dst,Mat_dst);
    			for(i=0;i<(Mat_dst1->rows*Mat_dst1->cols*3);i++)
    			{
    				Mat_dst1->data.fl[i]=Mat_dst->data.fl[i]/index;
    			}
    				
    			for(i=0;i<(Mat1->rows*Mat1->cols*3);i++)
    			{
    				Mat1->data.fl[i] = sqrt(pow(Mat_src->data.fl[i],2.0f)-pow(Mat_dst1->data.fl[i],2.0f));
    			}
    			cvAdd(Mat1,Mat2,Mat2);
    			for(i=0;i<(Mat3->height*Mat3->width*3);i++)
    			{
    				Mat3->data.fl[i] = Mat2->data.fl[i]/index;                   //残影部分
    			}
    			for(i=0;i<(Mat4->height*Mat4->width*3);i++)
    			{
    				Mat4->data.fl[i] =abs(Mat_dst1->data.fl[i]-Mat3->data.fl[i]);   //改进后的阵列
    			}
    			cvConvert(Mat1,advbackground);
    			cvShowImage("advback",advbackground);
    		cvConvert(Mat_dst1,background);
    		cvShowImage("back",background);
    		cvWaitKey(50);
    	}
    	cvDestroyWindow("video");
    	cvReleaseCapture( &capture );
    	return 0;
    }

# 实现效果 #

![Image 1][]

![Center 1][]

[20130915104534500]: /images/20221020/e44fd143832247bb8473d70a9e5d586a.png
[Image 1]: 
[Center]: /images/20221020/792c2a2b25b34d0baef63b0bff465d3b.png
[Center 1]: /images/20221020/c2d1aaaa56284ba0aaeea164b62d8d27.png