how do perform normalization of fingerprint image by dividing them into subimages?

i tried many codes please help me this is the concept. For each pixel (i, j) in a subimage, which is acquired by dividing the fingerprint image into subimages first, the normalized image is defined as follows: norimg(i, j) = M0 + coeff ∗ (img(i, j) −M) ; coeff = V0/V; Here, img(i, j) is the gray-level value of the fingerprint image in pixel (i, j), norimg(i, j) is the normalizing value in pixel (i, j), and coeff is the amplificatory multiple of the normalized image. M is the mean of the subimage, and V is the variance of the subimage. M0 and V0 are the desired mean and variance values, respectively. In the experiments, we usedM0 = 128 and V0 = 128 × 128.