谁帮我看看 这个指纹特征提取是根据什么方法提取的

zyp0987

%获取特征向量
function [vector] = feature_extract( flitered_image )
global img image center_x center_y band_num band_width wedge_num hole_radius gabor_num sector_length sector_num sector_index

length=sector_length;
s_num=sector_num+2;
s_size=length*length;

mean_s=zeros(s_num,1);
var_s=zeros(s_num,1);
num_s=zeros(s_num,1);
N=zeros(sector_length);

%获取特征向量
   
    for ( i=1:1:s_size)
        s_index=sector_index(i);
        s_index=s_index+1;
        
        mean_s(s_index)= mean_s(s_index)+flitered_image(i);
        num_s(s_index)=num_s(s_index)+1;
    end
   
    for (i=1:1:s_num)
        mean_s(i)=mean_s(i)/num_s(i);
    end
   
   
    for ( i=1:1:s_size)
        s_index=sector_index(i);
        s_index=s_index+1;
        
        var_s(s_index)= var_s(s_index) + (flitered_image(i)- mean_s(s_index))^2;      
    end
   
    for (i=1:1:s_num)
        var_s(i)= var_s(i) / num_s(i);
    end
   
    for (i=1:1:s_size)
        s_index=sector_index(i);
        s_index=s_index+1;   
        N(i)=var_s(s_index);
    end
   
    vector_tmp=zeros(s_num,1);
    for ( i=1:1:s_size)
        s_index=sector_index(i);
        s_index=s_index+1;
        
        vector_tmp(s_index)= vector_tmp(s_index) + abs(flitered_image(i)- mean_s(s_index));      
    end
   
    for (i=1:1:s_num)
        vector_tmp(i)=vector_tmp(i)/num_s(i);
    end     
   
    vector=vector_tmp;
最好 可以帮我每个注释下 帮助我理解下 谢谢！！！！！！！！