After extraction of minutiae, those minutiae between template and query fingerprint image should be paired. Because we have already coarsely aligned the template and query image,we only need to find a rotation angle to rotate the query image according to its reference point. Then two fingerprint images should be aligned. By pairing the minutiae, we could find the rotation angle.
The template and query image are firstly placed in a background which could contains both images. The center of the background is the position of reference points. The size of the
background normally should be 1.5~2 times of the original image size. The original image size in FVC 2002 [16] database 1 is 388X374. Here we select the size of the background as 700X700,
which is enough to place both images