Hybrid Images

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The Idea

This interesting hybrid-image idea was published in Siggraph'06 by people from MIT and U Glasgow,
Hybrid Images - A. Oliva, A. Torralba, P.G. Schyns, ACM Transactions on Graphics, vol. 25-3, pages 527-530, 2006.

The key is to combine the high frequency components of one image and the low frequency components of another image into a single image.

My Implementation

This synthesyzed hybrid image looks like one person from close up and looks like another person from five meters away.

The Procedure

  • Prepare two images that are roughly aligned.
It's me
Photo Curtersy by Changyin Zhou
  • Generate the output hybrid-image using the following equation in Fourier domain,

    where G is a Gaussian Filter.
     

The Code

  • To have a try, here is a simple Matlab implementation, hybridimg.m.
function hybridimg(ImgFile1, ImgFile2, ImgFileOut)
% Hybrid Image Generator
% Usage: hybridimg(<Img1 Filename>, <Img2 Filename>, <ImgOutput Filename>);

   radius = 13; % Param of the Gaussian radius

   I1 = imread(ImgFile1);
   I2 = imread(ImgFile2);
   I1_ = fftshift(fft2(double(I1)));
   I2_ = fftshift(fft2(double(I2)));
   [m n z] = size(I1);
   h = fspecial('gaussian', [m n], radius);
   h = h./max(max(h));
   for colorI = 1:3
      J_(:,:,colorI) = I1_(:,:,colorI).*(1-h) + I2_(:,:,colorI).*h;
   end
   J = uint8(real(ifft2(ifftshift(J_))));
   imwrite(J, ImgFileOut);
end

 

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Page last updated: December 18, 2007 10:05 AM