1[10 x 10]=>[20 x 20], interp err = 1.9079e+00
2[20 x 20]=>[40 x 40], interp err = 3.7490e-01
3[40 x 40]=>[80 x 80], interp err = 7.6222e-02
4[80 x 80]=>[160 x 160], interp err = 1.7144e-02
5[160 x 160]=>[320 x 320], interp err = 4.0510e-03
6[320 x 320]=>[640 x 640], interp err = 9.8338e-04
7