www.pudn.com > mulscal_edge.rar > local_max_mode.asv

%求纵向细节v和横行细节h的合成及模极大值 
function [out1,out2] = local_max_mode(v,h,thr,a0,n); 
 
[row,col] =size(v); 
 
for irow=1:row 
    for jcol=1:col 
        mf(irow,jcol) = sqrt(v(irow,jcol)^2 + h(irow,jcol)^2); 
        af(irow,jcol) = atand(v(irow,jcol)/(h(irow,jcol)+eps)); 
    end 
end 
 
max_mf=mf; 
m1=(n+1)/2;%n为奇数是模板的大小 
m2=(n-1)/2; 
 
max_mf=wthresh(mf,'h',thr); 
temp_mf=max_mf; 
%对模长取自适应阀值 
for irow=m1:(row-m1) 
    for jcol=m1:(col-m1) 
        if max_mf(irow,jcol)>0 
           lefttop_h=irow-m2;%左上角横坐标 
           lefttop_v=jcol-m2;%左上角纵坐标 
           sub_c=sub_m(max_mf,lefttop_h,lefttop_v,n); 
%            mean_arry=mean(sub_c); 
%            mean_thr=mean(mean_arry); 
%            sub_c=wthresh(sub_c,'h',mean_thr); 
           if rank_c(sub_c,max_mf(irow,jcol),m1^2) 
              temp_mf(irow,jcol)=0; 
           else 
              mean_array=mean(sub_c); 
              adapt_thr=mean(mean_array)*a0; 
              temp_mf(irow,jcol)=wthresh(max_mf(irow,jcol),'h',adapt_thr); 
           end 
        end 
    end 
end 
edge_mf=temp_mf; 
 
 
max_mf=mf; 
edge_mf(row,col)=0;%模的极大值 
% grad(row,col)=-1;%梯度方向 
 
% -1代表非极值点 
% 0代表-22.5度至22.5度 
% 1代表22.5度至67.5度 
% 3代表-22.5度至-67.5度 
% 2代表67.5度至90度以及-67.5度至-90度 
 
for irow=2:row-1 
    for jcol=2:col-1 
       if max_mf(irow,jcol)<=0 
          if max_mf(irow,jcol)>=max_mf(irow+1,jcol) 
             edge_mf(irow,jcol) = max_mf(irow,jcol); 
          else 
             edge_mf(irow,jcol)=0; 
          end 
       end 
       atan_temp=af(irow,jcol); 
       switch atan_temp 
           case (atan_temp>=-22.5)&(atan_temp<22.5) 
                if (max_mf(irow,jcol+1)<=max_mf(irow,jcol))&(max_mf(irow,jcol-1)<=max_mf(irow,jcol)) 
                    edge_mf(irow,jcol) = max_mf(irow,jcol); 
                end 
           case (atan_temp>=22.5)&(atan_temp<67.5) 
                 
                if (max_mf(irow-1,jcol+1)<=max_mf(irow,jcol))&(max_mf(irow+1,jcol-1)<=max_mf(irow,jcol)) 
                    edge_mf(irow,jcol) = max_mf(irow,jcol); 
                end 
           case (atan_temp>=-67.5)&(atan_temp<-22.5) 
                if (max_mf(irow-1,jcol-1)<=max_mf(irow,jcol))&(max_mf(irow+1,jcol+1)<=max_mf(irow,jcol)) 
                    edge_mf(irow,jcol) = max_mf(irow,jcol); 
                end 
           otherwise 
                if (max_mf(irow-1,jcol)<=max_mf(irow,jcol))&(max_mf(irow+1,jcol)<=max_mf(irow,jcol)) 
                    edge_mf(irow,jcol) = max_mf(irow,jcol); 
                end 
       end %end switch 
        
   end 
end 
 
out1 = edge_mf; 
out2 = af;