hey can u help me that how can i make my zernike moment code, invariant to rotation.

[Matt Kindig]

You haven't shown us any code!

[tamanna]

n=4;

m=2

p = rgb2gray(imread('C:\Users\hp\Desktop\2.JPG'));

N = size(p,1);

[ZOH AOH PhiOH] = Zernikmoment(p,n,m); 

function [Z A Phi] = Zernikmoment(p,n,m)

N = size(p,1);

x = 1:N; y = x;

[X,Y] = meshgrid(x,y);

R = sqrt((2.*X-N-1).^2+(2.*Y-N-1).^2)/N;

Theta = atan2((N-1-2.*Y+2),(2.*X-N+1-2));

R = (R<=1).*R;

Rad = radialpoly(R,n,m);    % get the radial polynomial

Product = p(x,y).*Rad.*exp(-1i*m*Theta);

Z = sum(Product(:));        % calculate the moments

cnt = nnz(R)+1;          % count the number of pixels inside the unit circle 

Z = (n+1)*Z/cnt;            % normalize the amplitude of moments

A = abs(Z);                 % calculate the amplitude of the moment

Phi = angle(Z)*180/pi;      % calculate the phase of the mement    

function rad = radialpoly(r,n,m)

rad = zeros(size(r));                     % Initilization

for s = 0:(n-abs(m))/2

    c = (-1)^s*factorial(n-s)/(factorial(s)*factorial((n+abs(m))/2-s)*factorial((n-abs(m))/2-s));

    rad = rad + c*r.^(n-2*s);

end

this code work well with 0, 90 and 180 degree but not with 30 or 45 degree.

[Walter Roberson]

What should be looked at to determine whether it is doing well or not?

[tamanna]

sir..it is doing well but i want to make my program rotation invariant. how should i do ??

Answer 1

[arun anoop m]

How can i get angle and magnitude as output image instead features?

A = abs(Z); % calculate the amplitude of the moment

Phi = angle(Z)*180/pi; % calculate the phase of the mement

How to get ,

figure,imshow(A) ?

figure,imshow(Phi) ?