Fast 2D cross correlation algorithm

1. How do you calculate 2D cross-correlation?
2. What is NCC algorithm?
3. How does 2D correlation work?
4. How do you cross-correlation in Matlab?

How do you calculate 2D cross-correlation?

c = xcorr2( a , b ) returns the cross-correlation of matrices a and b with no scaling. xcorr2 is the two-dimensional version of xcorr . c = xcorr2( a ) is the autocorrelation matrix of input matrix a . This syntax is equivalent to xcorr2(a,a) .

What is NCC algorithm?

Normalized Cross-Correlation (NCC) is by definition the inverse Fourier transform of the convolution of the Fourier transform of two (in this case) images, normalized using the local sums and sigmas (see below).

How does 2D correlation work?

As mostly spectroscopic signals are discussed, sometime also two dimensional correlation spectroscopy is used and refers to the same technique. In 2D correlation analysis, a sample is subjected to an external perturbation while all other parameters of the system are kept at the same value.

How do you cross-correlation in Matlab?

r = xcorr( x , y ) returns the cross-correlation of two discrete-time sequences. Cross-correlation measures the similarity between a vector x and shifted (lagged) copies of a vector y as a function of the lag.