www.pudn.com > Normal_encoding.rar > encode.m

% encode - generates a biometric template from the normalised iris region, 
% also generates corresponding noise mask 
% 
% Usage:  
% [template, mask] = encode(polar_array,noise_array, nscales,... 
% minWaveLength, mult, sigmaOnf) 
% 
% Arguments: 
% polar_array       - normalised iris region 
% noise_array       - corresponding normalised noise region map 
% nscales           - number of filters to use in encoding 
% minWaveLength     - base wavelength 
% mult              - multicative factor between each filter 
% sigmaOnf          - bandwidth parameter 
% 
% Output: 
% template          - the binary iris biometric template 
% mask              - the binary iris noise mask 
% 
% Author:  
% Libor Masek 
% masekl01@csse.uwa.edu.au 
% School of Computer Science & Software Engineering 
% The University of Western Australia 
% November 2003 
 
function [template, mask] = encode(polar_array,noise_array, nscales, minWaveLength, mult, sigmaOnf) 
 
% convolve normalised region with Gabor filters 
[E0 filtersum] = gaborconvolve(polar_array, nscales, minWaveLength, mult, sigmaOnf); 
 
length = size(polar_array,2)*2*nscales; 
 
template = zeros(size(polar_array,1), length); 
 
length2 = size(polar_array,2); 
h = 1:size(polar_array,1); 
 
%create the iris template 
 
mask = zeros(size(template)); 
 
for k=1:nscales 
     
    E1 = E0{k}; 
     
    %Phase quantisation 
    H1 = real(E1) > 0; 
    H2 = imag(E1) > 0; 
     
    % if amplitude is close to zero then 
    % phase data is not useful, so mark off 
    % in the noise mask 
    H3 = abs(E1) < 0.0001; 
     
     
    for i=0:(length2-1) 
                 
        ja = double(2*nscales*(i)); 
        %construct the biometric template 
        template(h,ja+(2*k)-1) = H1(h, i+1); 
        template(h,ja+(2*k)) = H2(h,i+1); 
         
        %create noise mask 
        mask(h,ja+(2*k)-1) = noise_array(h, i+1) | H3(h, i+1); 
        mask(h,ja+(2*k)) =   noise_array(h, i+1) | H3(h, i+1); 
         
    end 
     
end