A Passive 3D Face Recognition System and Its Performance Evaluation
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
Phase information and space filling curves in noisy motion estimation
IEEE Transactions on Image Processing
High-accuracy sub-pixel motion estimation from noisy images in Fourier domain
IEEE Transactions on Image Processing
Phase-only correlation based matching in scrambled domain for preventing illegal matching
Transactions on data hiding and multimedia security V
Multidimensional Systems and Signal Processing
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In this paper, we establish the exact relationship between the continuous and the discrete phase difference of two shifted images, and show that their discrete phase difference is a two-dimensional sawtooth signal. Subpixel registration can, thus, be performed directly in the Fourier domain by counting the number of cycles of the phase difference matrix along each frequency axis. The subpixel portion is given by the noninteger fraction of the last cycle along each axis. The problem is formulated as an overdetermined homogeneous quadratic cost function under rank constraint for the phase difference, and the shape constraint for the filter that computes the group delay. The optimal tradeoff for imposing the constraints is determined using the method of generalized cross validation. Also, in order to robustify the solution, we assume a mixture model of inlying and outlying estimated shifts and truncate our quadratic cost function using expectation maximization.