MATLAB: Has anyone implemented moravec corner detector in matlab?

corner detectionimage processing

This is what i have tried.But with very less accurate.
    clear all
close all
clc
tic
I=imread('panorama_image1.jpg');
originalmap=I;
w=5;
m=floor(size(I,1)/w);
n=floor(size(I,2)/w);
c=ceil(w/2)+(0:n-1)*w;
r=ceil(w/2)+(0:m-1)*w;
step=floor(w/2);
for y_unit=1:m
    for x_unit=1:n 
        v1=0;v2=0;v3=0;v4=0; 
        for i=-step:step-1 
            v1=v1+(I(r(y_unit),c(x_unit)+i)-I(r(y_unit),c(x_unit)+i+1))^2; 
            v2=v2+(I(r(y_unit)+i,c(x_unit)+i)-I(r(y_unit)+i+1,c(x_unit)+i+1))^2; 
            v3=v3+(I(r(y_unit)+i,c(x_unit))-I(r(y_unit)+i+1,c(x_unit)))^2; 
            v4=v4+(I(r(y_unit)-i,c(x_unit)+i)-I(r(y_unit)-i-1,c(x_unit)+i+1))^2; 
        end 
        IV_cr(y_unit,x_unit)=min([v1,v2,v3,v4]); 
    end 
end
exper_thr=20;
IV_cr(IV_cr<exper_thr)=NaN;
wf=9;
mf=floor(m/wf);
nf=floor(n/wf);
xc=[];
yc=[]; for y_unit=1:mf
    for x_unit=1:nf 
        [C,I]=max(IV_cr((y_unit-1)*wf+1:y_unit*wf,(x_unit-1)*wf+1:x_unit*wf))
        [C1,I1]=max(C); 
        IV_crch(y_unit,x_unit)=C1;
        row=I(I1); 
        col=I1; 
        crch_row(y_unit,x_unit)=(y_unit-1)*wf+row;
        crch_col(y_unit,x_unit)=(x_unit-1)*wf+col;
        yc=[yc,r((y_unit-1)*wf+row)];xc=[xc,c((x_unit-1)*wf+col)]; 
        IV_cr((y_unit-1)*wf+1:y_unit*wf,(x_unit-1)*wf+1:x_unit*wf)=NaN; 
        IV_cr((y_unit-1)*wf+row,(x_unit-1)*wf+col)=C1; 
    end 
end 
figure(1) 
imshow(originalmap)
figure(2)
plot(xc,yc,'*')
view(0,-90)
toc;
t=toc;
disp(['amount of time',num2str(t),'sec'])
figure(3)
imshow(originalmap)
hold on
plot(xc,yc,'R*')
axis on
end

Best Answer

I just did if for you:
function C = moravec(I)
%MORAVEC Moravec corner detector
%

%   C = MORAVEC(I)
%
%   Thorsten.Hansen@psychol.uni-giessen.de  2015-05-20
if nargin == 0 % simple test
  I = zeros(100);
  I(40:60, 40:60) = 1;
  C = moravec(I);
  imshow(0.5*C+I, [])
  if nargout == 0, clear C, end
  return
end
D(:,:,1) = diff([I I(:,end)]')';
D(:,:,2) = diff([I(:,1) I]')';
D(:,:,3) = diff([I; I(end,:)]);
D(:,:,4) = diff([I(1,:); I]);
C = sum(D.^2, 3);
if nargout == 0, clear C, end
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