NCC as its name, is used to describe the degree of correlation of two goals, that can be used to describe the similarity between the target. NCC will generally be used for image matching, i.e. a search for the highest matching image corresponding region of NCC as a small area known, and then align the entire image.
Suppose two images 
, then the NCC can be calculated as follows:
Which 
represents a point multiplication.
For example, the following two images, we want to align
First, the selected area has two images as one image in templete
And select the region including templete another image
The final results are aligned
