Method
Given two input images and :
Apply a window function (e.g., a Hamming window) on both images to reduce edge effects. Then, calculate the discrete 2D Fourier transform of both images.
Calculate the cross-power spectrum by taking the complex conjugate of the second result, multiplying the Fourier transforms together elementwise, and normalizing this product elementwise.
Obtain the normalized cross-correlation by applying the inverse Fourier transform.
Determine the location of the peak in .
Commonly, interpolation methods are used to estimate the peak location to non-integer values, despite the fact that the data are discrete. Because the Fourier representation of the data has already been computed, it is especially convenient to use the Fourier shift theorem with real-valued shifts for this purpose. It is also possible to infer the peak location from phase characteristics in Fourier space without the inverse transformation, as noted by Stone
Read more about this topic: Phase Correlation
Famous quotes containing the word method:
“One of the grotesqueries of present-day American life is the amount of reasoning that goes into displaying the wisdom secreted in bad movies while proving that modern art is meaningless.... They have put into practise the notion that a bad art work cleverly interpreted according to some obscure Method is more rewarding than a masterpiece wrapped in silence.”
—Harold Rosenberg (1906–1978)
“I have a new method of poetry. All you got to do is look over your notebooks ... or lay down on a couch, and think of anything that comes into your head, especially the miseries.... Then arrange in lines of two, three or four words each, don’t bother about sentences, in sections of two, three or four lines each.”
—Allen Ginsberg (b. 1926)
“No method nor discipline can supersede the necessity of being forever on the alert. What is a course of history or philosophy, or poetry, no matter how well selected, or the best society, or the most admirable routine of life, compared with the discipline of looking always at what is to be seen? Will you be a reader, a student merely, or a seer? Read your fate, see what is before you, and walk on into futurity.”
—Henry David Thoreau (1817–1862)