to perform iris normalisation
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Need matlab code to perform irid normalisation
Réponses (2)
Walter Roberson
le 14 Sep 2011
0 votes
Please clarify the difference between this question and your earlier question, http://www.mathworks.com/matlabcentral/answers/15183-coding-for-implementing-gaussian-filter-in-iris-recognition-system
omar mohamed
le 10 Déc 2012
Modifié(e) : Walter Roberson
le 29 Juin 2017
function imP = ImToPolar (imR, rMin, rMax, M, N)
% IMTOPOLAR converts rectangular image to polar form. The output image is
% an MxN image with M points along the r axis and N points along the theta
% axis. The origin of the image is assumed to be at the center of the given
% image. The image is assumed to be grayscale.
% Bilinear interpolation is used to interpolate between points not exactly
% in the image.
%
% rMin and rMax should be between 0 and 1 and rMin < rMax. r = 0 is the
% center of the image and r = 1 is half the width or height of the image.
%
% V0.1 7 Dec 2007 (Created), Prakash Manandhar pmanandhar@umassd.edu
[Mr Nr] = size(imR); % size of rectangular image
Om = (Mr+1)/2; % co-ordinates of the center of the image
On = (Nr+1)/2;
sx = (Mr-1)/2; % scale factors
sy = (Nr-1)/2;
imP = zeros(M, N);
delR = (rMax - rMin)/(M-1);
delT = 2*pi/N;
% loop in radius and
for ri = 1:M
for ti = 1:N
r = rMin + (ri - 1)*delR;
t = (ti - 1)*delT;
x = r*cos(t);
y = r*sin(t);
xR = x*sx + Om;
yR = y*sy + On;
imP (ri, ti) = interpolate (imR, xR, yR);
end
end
function v = interpolate (imR, xR, yR)
xf = floor(xR);
xc = ceil(xR);
yf = floor(yR);
yc = ceil(yR);
if xf == xc & yc == yf
v = imR (xc, yc);
elseif xf == xc
v = imR (xf, yf) + (yR - yf)*(imR (xf, yc) - imR (xf, yf));
elseif yf == yc
v = imR (xf, yf) + (xR - xf)*(imR (xc, yf) - imR (xf, yf));
else
A = [ xf yf xf*yf 1
xf yc xf*yc 1
xc yf xc*yf 1
xc yc xc*yc 1 ];
r = [ imR(xf, yf)
imR(xf, yc)
imR(xc, yf)
imR(xc, yc) ];
a = A\double(r);
w = [xR yR xR*yR 1];
v = w*a;
end
end
3 commentaires
pawarcse
le 29 Juin 2017
Sir can you please tell us what should be the value of Mr and Nr??
Walter Roberson
le 29 Juin 2017
Mr and Nr will be assigned the size of the input image iMR.
Note: iMR should be 2D (grayscale) not RGB.
pawarcse
le 4 Juil 2017
Thank you very much sir!!
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