www.pudn.com > MI_Optimization.rar > opti_MI_scaling.asv

% 2D Mutual Information Matching using Optimization toolbox 
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% In image.mat, IM1 and IM2 are included. 
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% IM1: 230 X 230 MRI image 
% IM2: 512 X 512 CT image 
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% Your selection of initial point x0 is critical for this matching. 
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% x0(1): First index of row for cropping the rotated IM2 with x0(3) angle 
% x0(2): First index of column for cropping the rotated IM2 with x0(3) angle 
% x0(3): Angle 
% x0(4): Scale factor 
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% The 'fminsearch' function in the Optimization Toolbox is used.   
% The objection function is 'image_registr_MI.m' 
close all 
clear all 
 
tic 
 
x0=[50; 50; -15; 0.5]; % Initial points, [X, Y, angle, scaling]  
                       % Select them as close to the matching points as possible 
                       % by guessing; otherwize, it will fail. 
 
[x, fval]=fminsearch(@image_registr_MI,x0) % Optimization using 'fminsearch' 
 
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% Display 
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load image 
 
IM1=double(IM1); 
IM2=double(IM2); 
IM2=imresize(IM2, x(4), 'bilinear'); 
J=imrotate(double(IM2), x(3),'bilinear'); %rotated cropped IMAGE2 
 
[n1 n2]=size(IM1); 
[n3 n4]=size(J); 
position=1:n1; 
xx=round(position+x(1)); 
yy=round(position+x(2)); 
 
IM2=round(J(xx, yy)); 
 
subplot(1,2,1), imshow(IM1, [ ]), title('Image 1') 
subplot(1,2,2), imshow(IM2, [ ]), title('Registered Image 2') 
 
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