MeanShift运动目标跟踪 matlab程序

MeanShift运动目标跟踪matlab程序

思路简介：

1.截取跟踪目标矩阵rect

2.求取跟踪目标的加权直方图hist1

3.读取视频序列中的一帧，先随机取一块与rect等大的矩形，计算加权直方图hist2。

4.计算两者比重函数，如果后者差距过大，更新新的矩阵中心Y，进行迭代（MeanShift 是一种变步长可以迅速接近概率密度峰值的方法），直至一定条件后停止。

源程序（参考过其他程序）：

[plain]view plaincopy

1.

function [] = select()

close all;

clear all;

%%%%%%%%%%%%%%%%%%根据一幅目标全可见的图像圈定跟踪目标%%%%%%%%%%%%%%%%%%%%%%%

I=imread('E:\数字图像处理\6\2\18.bmp');

figure(1);

imshow(I);

[temp,rect]=imcrop(I);

[a,b,c]=size(temp);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%计算目标图像的权值矩阵%%%%%%%%%%%%%%%%%%%%%%%

y(1)=a/2;

y(2)=b/2;

tic_x=rect(1)+rect(3)/2;

tic_y=rect(2)+rect(4)/2;

m_wei=zeros(a,b);%权值矩阵

h=y(1)^2+y(2)^2 ;%带宽

for i=1:a

for j=1:b

dist=(i-y(1))^2+(j-y(2))^2;

m_wei(i,j)=1-dist/h; %epanechnikov profile

end

end

C=1/sum(sum(m_wei));%归一化系数

%计算目标权值直方图qu

%hist1=C*wei_hist(temp,m_wei,a,b);%target model

hist1=zeros(1,a*b);

for i=1:a

for j=1:b

%rgb颜色空间量化为16*16*16 bins

q_r=fix(double(temp(i,j,1))/16); %fix为趋近0取整函数

q_g=fix(double(temp(i,j,2))/16);

q_b=fix(double(temp(i,j,3))/16);

q_temp=q_r*256+q_g*16+q_b; %设置每个像素点红色、绿色、蓝色分量所占比重

hist1(q_temp+1)= hist1(q_temp+1)+m_wei(i,j); %计算直方图统计中每个像素点占的权重

end

end

hist1=hist1*C;

rect(3)=ceil(rect(3));

rect(4)=ceil(rect(4));

%%%%%%%%%%%%%%%%%%%%%%%%%读取序列图像

myfile=dir('*.bmp');

lengthfile=length(myfile);

for l=1:lengthfile

Im=imread(myfile(l).name);

num=0;

Y=[2,2];

%%%%%%%mean shift迭代

while((Y(1)^2+Y(2)^2>0.5)&num<20) %迭代条件

num=num+1;

temp1=imcrop(Im,rect);

%计算侯选区域直方图

%hist2=C*wei_hist(temp1,m_wei,a,b);%target candidates pu

hist2=zeros(1,a*b);

for i=1:a

for j=1:b

q_r=fix(double(temp1(i,j,1))/16);

q_g=fix(double(temp1(i,j,2))/16);

q_b=fix(double(temp1(i,j,3))/16);

q_temp1(i,j)=q_r*256+q_g*16+q_b;

hist2(q_temp1(i,j)+1)= hist2(q_temp1(i,j)+1)+m_wei(i,j);

end

end

hist2=hist2*C;

figure(2);

subplot(1,2,1);

plot(hist2);

hold on;

w=zeros(1,a*b);

for i=1:a*b

if(hist2(i)~=0)

w(i)=sqrt(hist1(i)/hist2(i));

else

w(i)=0;

end

end

%变量初始化

sum_w=0;

xw=[0,0];

for i=1:a;

for j=1:b

sum_w=sum_w+w(uint32(q_temp1(i,j))+1);

xw=xw+w(uint32(q_temp1(i,j))+1)*[i-y(1)-0.5,j-y(2)-0.5];

end

end

Y=xw/sum_w;

%中心点位置更新

rect(1)=rect(1)+Y(2);

rect(2)=rect(2)+Y(1);

end

%%%跟踪轨迹矩阵%%%

tic_x=[tic_x;rect(1)+rect(3)/2];

tic_y=[tic_y;rect(2)+rect(4)/2];

v1=rect(1);

v2=rect(2);

v3=rect(3);

v4=rect(4);

%%%显示跟踪结果%%%

subplot(1,2,2);

imshow(uint8(Im));

title('目标跟踪结果及其运动轨迹');

hold on;

plot([v1,v1+v3],[v2,v2],[v1,v1],[v2,v2+v4],[v1,v1+v3],[v2+v4,v2+v4],[v1+v3,v1+v3],[v2, v2+v4],'LineWidth',2,'Color','r');

plot(tic_x,tic_y,'LineWidth',2,'Color','b');

end

结果截图：