相位相关法求图像平移量

[lailaigu]

大家好，我用相位相关法求图像之间的平移量，
%%%
function [row,col] = PCdemo(I,I2);
%I,I2 are reference and target images
%[row, col] are row, column shifts
%

%Fourier transform both images
fi = fft2(double(I));
fr = fft2(double(I2));

%Perform phase correlation (amplitude is normalized)
fc = fi.*conj(fr);
fcn = fc./abs(fc);

%Inverse fourier of peak correlation matrix and max location
peak_correlation_matrix = abs(ifft2(fcn));
[peak, idx] = max(peak_correlation_matrix(:));

%Calculate actual translation
[row,col] = ind2sub(size(peak_correlation_matrix),idx);

if row < size(peak_correlation_matrix,1)/2
row = -(row -1);
else
row = size(peak_correlation_matrix,1) - (row -1);
end;
if col < size(peak_correlation_matrix,2)/2;
col = -(col-1);
else
col = size(peak_correlation_matrix,2) - (col -1);
end
end

这一段程序中的蓝色部分是什么意思，我没有看懂。

[niubenbenxuexi]

用来计算图像的偏移量。