Не могу найти ошибку

clear all;
close all;
[filename, pathname] = uigetfile({'*.jpg;*.tif;*.png;*.gif;*.bmp','All Image Files';...
          '*.*','All Files' },'mytitle',...
          'C:\Work\myfile.jpg')
img = imread(filename);
img=mean(img,3);
[ligneorigine colonneorigine]=size(img);
 
taille=1;
%effet de bord
img = wextend(2,'zpd',img,1);
[ligne colonne]=size(img);
d=zeros(ligne,colonne);
 
for i = taille+1 : ligne-(taille+1)
    for j = taille+1 : colonne -(taille+1)
        d(i,j)=min( (img(i,j-1)-img(i,j))^2+(img(i,j+1)-img(i,j))^2 ,...
                    (img(i-1,j)-img(i,j))^2+(img(i+1,j)-img(i,j))^2 );
    end
    i
end
 
threshold = 50;
d(d<=threshold)=0;
d(d>threshold)=1;
m=zeros(ligne,colonne);
 
%threshold = 35000;
for i = taille+1 : ligne-(taille+1)
    for j = taille+1 : colonne -(taille+1)
        if d(i,j)~=0
            c=min( (img(i,j-1)-img(i,j))^2+(img(i,j+1)-img(i,j))^2 ,...
                    (img(i-1,j)-img(i,j))^2+(img(i+1,j)-img(i,j))^2 );
            B1= (img(i-1,j)-img(i,j-1))*(img(i,j-1)-img(i,j))+(img(i+1,j)-img(i,j+1))*(img(i,j+1)-img(i,j));
            B2= (img(i-1,j)-img(i,j+1))*(img(i,j+1)-img(i,j))+(img(i+1,j)-img(i,j-1))*(img(i,j-1)-img(i,j));
            RA=(img(i,j-1)-img(i,j))^2+(img(i,j+1)-img(i,j))^2;
            RB=(img(i-1,j)-img(i,j))^2+(img(i+1,j)-img(i,j))^2;
            C= RA;
            B=min(B1,B2);
            A= RB-RA-2*B;
            if B<0 && (A+B)>0
                m(i,j)=C-(B^2/A);
            else
                m(i,j)=c;
            end
        else
            m(i,j)=0;
        end
    end
    i
end
 
m = m(taille:end-taille-1,taille:end-taille-1);
threshold = 1000;
m(m<=threshold)=0;
 
[imax,vmax]= maxlocaux(m,10);
figure(  'name','détection de coin Trajkovic 4 voisins',...
            'NumberTitle','off',...
            'MenuBar','none',...
            'color',[0.3137 0.3137 0.5098]);
imshow(uint8(img))
hold on
nb=200;
if length(imax)>nb
    nbcorner = nb;
else
    nbcorner=length(imax);
end
for i = 1 :  nbcorner %length(imax)
    plot([vmax(i,2)-2 vmax(i,2)-2 vmax(i,2)+2 vmax(i,2)+2 vmax(i,2)-2],...
        [vmax(i,1)-2 vmax(i,1)+2 vmax(i,1)+2 vmax(i,1)-2 vmax(i,1)-2] ,'r','LineWidth',1)
end