avec transformations.py

import transformations
m = 12609
n = 8810
fp = [[1,m,m,1],[1,1,n,n]]
tp = [[1616411.91,1617482.52,1617503.82,1616433.22],[9173672.33,9173641.84,9174389.85,9174420.34]]
M = transformations.affine_matrix_from_points(fp, tp)
print M
array([[  8.49147367e-02,   2.41854921e-03,   1.61641183e+06],
       [ -2.41830584e-03,   8.49142922e-02,   9.17367225e+06],
       [  0.00000000e+00,   0.00000000e+00,   1.00000000e+00]])