normxcorr2(matrix4X4, matrix4X4); // Builtin Function.

 % NCC=cov(a,b)/sqrt(var(a)var(b))

   matrix4X4Vector =   matrix4X4(:);
   mMean = mean(matrix4X4Vector)
   meanMatrix4X4Vector = (matrix4X4Vector - mMean);

    varianceMain     = var(meanMatrix4X4Vector);
    varianceTemplate = var(meanMatrix4X4Vector);

    denominator= sqrt(varianceMain * varianceTemplate);

    numerator = conv(meanMatrix4X4Vector, meanMatrix4X4Vector);
    ncc = numerator/denominator;